1. Find a sunny, warm area 1m2 and clear it of vegetation.
2. Lay a base of gravel for good drainage
3. Bees prefer loamy soil, but if you don’t have any try to replicate loamy soil by mixing one bag of builders’ sand with 2 bags of top soil to get a good consistency that binds together.
4. Add it little by little on top of the gravel, layer by layer, patting it down as you go.
5. Keep going until you have a 400mm high mound.
6. Add some large stones/pebbles to the base as some bees may bask on them to warm up, or they may shelter underneath or behind on windy days, or make their holes in between the stones.
7. Monitor to see if any holes are made and who may be nesting in your sand mound.
Thanks to Dr Konstantinos Tsiolis, whose PhD was on nesting sites for mining bees, for his advice and help with this project.
This month, we have to say goodbye to some of my favourite spring-flying solitary bees, like the Hairy-footed flower bees and the Red mason bees, as their short life-cycles come to end. But we can say hello to some summer beauties, like the Wool carder bee and the leafcutter bees. You’ll hopefully see three more bumblebee species too and a cuckoo bumblebee, (There will also be plenty of buff-tailed and white-tailed bumblebee workers foraging, and smaller, brown common carder bees, but we haven’t included them in the June guide as we wanted to introduce you to some new faces). There are four new solitary bees to try to identify this month: a lovely mason bee, a small, zippy flower bee with huge green eyes, and we’ll see for the first time this year, leafcutter bees. And see if you can spot the difference between a bumblebee and a hoverfly that mimics a bumblebee.
Tips for IDing June bumblebees:
Early bumblebee (Bombus pratorum) – if you see a small bumblebee (9 -13mm) with a faint red bottom and yellow stripes, it’s an early bumblebee. The male (pictured above) is particularly striking with his bright-yellow fluffy facial hairs and a stripe on his body too. This month, new queens may be emerging, along with workers and the males. Look out for them on cotoneasters, brambles, Raspberry and Crane’s-bill (hardy geraniums). They can also nectar rob from longer, tubular flowers. They have small colonies of up to 100 bees and generally nest underground in old rodent burrows like many bumblebee species, but they can also inhabit bird boxes (like Tree bumblebees (Bombus hypnourm) and nest in roof spaces and holes in trees, although I have yet to hear reports of this.
Garden bumblebee (Bombus hortorum) – sit by a patch of flowering foxgloves or honeysuckle and you will hopefully see this long-tongue bumblebee coming in and out of the flowers. The way to tell the Garden bumblebee from Buff-tailed and White-tailed bumblebees is by looking at the two golden bands at the front and back of the thorax which makes the bee look as if it’s wearing a black skull cap. It has a third band on the abdomen. It also has a longer ‘horsey’ face than other bumblebees, and will be going into the flower rather than sucking up the nectar from the side. Many other large bumblebees with white tails have shorter tongues but nectar rob by making a hole in the base of the flower.
Red-tailed bumblebee (Bombus lapidarius) –unmissable with jet black bodies and fiery red tails, but records show that they too are becoming less widespread. I have read that they favour yellow flowers, so I am planting lots of Birds-foot trefoil for them, but so far no luck in my London garden. I have seen them on a rooftop on a tiny yellow sedum’s flowers and collecting pollen from the pink-petaled seaside daisy (Erigeron glaucus). I’d also suggest looking up at Laburnum trees drooping under the weight of yellow, pea-like flowers. This year I saw many foraging on purple salvia flowers in a garden in north Norfolk. In the photo above the female is putting up a leg as a warning signal that she feels threatened and to keep away. But these are gentle bees.
Vestal cuckoo bee (Bombus vestalis) – also called the Southern cuckoo bee because it is in this part of England where you are most likely to see the huge females (24mm) seeking to invade the underground nest of Buff-tailed bumblebees (Bombus terrestris) and lay their eggs. At this time of year only smaller Buff-tailed bumblebee workers are foraging. So if you see a huge bee that looks like a big Buff-tailed bumblebee queen, it’s more likely to be its cuckoo. Other ID tips: she has a longer white tail with yellow hairs at the base, and there are NO pollen baskets on her hind legs. (She is a female and not a queen because she doesn’t have worker bees. Her eggs hatch into females and males that are fed by the Buff-tailed bumblebees worker bees. These workers become the cuckoo bee’s slaves after she takes over their mother’s nest.) NOTE: There are 6 Cuckoo bumblebee species in the UK. This is the most common one because its host is the most common bumblebee.
How to ID June solitary bees:
Green-eyed flower bee (Anthophora bimaculata) – these gorgeous looking bees with their stunning big green eyes are around half the size (8mm) of the spring-flying Hairy-footed flower bees (Anthophora plumipes). Their diminutive size, along with their rapid darting movement between flowers, makes them much more difficult to spot and they are largely confined to southern England, especially coastal areas and heathland where they nest in large, noisy aggregations in sandy cliff tops and the edge of costal pathways. They feed on Vipers bugloss, Black horehound, brambles, Thyme and mints including Nepeta and other garden catmints. Listen out for the high-pitched buzz as they feed, often in groups. They fly until September, so one to watch out for if you’re holidaying on the South cost this summer.
The Orange-vented mason bee (Osmia leaiana) – has a fluffy orange pollen brush under her abdomen which she uses to collect pollen from a variety of flowers including Green Alkanet, Crane’s-bill (hardy geraniums), brambles and knapweeds. You may see her nesting in a bee hotel, or a bee observation box. Here is a video of her packing her nest with pollen (we mistakenly called her a Blue mason bee because they fly at similar times of the year and both use masticated leaf to plug the tubes of their nest).
Patchwork leafcutters (Megachile cenuncularis) are one of the most common leafcutter bees found in gardens. They get their name, like many solitary bees, from how they construct their nests. They cut pieces of leaf from many plants including rose and lilac bushes, honeysuckles, willowherbs, Amelanchier trees, birches and Horse chestnut to make their nests, leaving the leaves looking as if they has been attacked by a hole punch. This leafcutter bee is a little smaller (9-10mm) than a honeybee and a brownish grey colour. But the easier way to tell her apart from a honeybee is from the orange pollen brush on the whole underside of her tummy, (similar to the Orange-vented mason bee), which she has a habit of lifting up in the air while feeding on flowers. Favourites include thistles, knapweeds, burdock, Common Fleabane, Bird’s-foot trefoil, St John’s-wort and brambles. They nest in bee hotels if Red mason bees have left any tubes unoccupied. They plug the entrance with pieces of leaf later in the summer when they have laid all their eggs in a tube. If you’re very lucky, you may see a female flying with a piece of leaf as big as herself clasped between her legs. They can also nest in dead wood, cavities in walls and even occasionally in soil. TOP TIP: How to tell a Orange-vented mason bee from a leafcutter – with difficultly, but the mason bee is a fraction smaller (8mm), but has a bigger head and narrower body and uses chewed up leaf to construct her nest, rather than discs of leaves.
The Wool Carder Bee (Anthidium manicatum) is an easy bee to spot and therefore one of my favourites. It’s a chunky 16mm bee with yellow spots that looks like stitching along the side of its abdomen . And if you plant Lamb’s Ear (Stachys byzantina), you are guaranteed to see females collecting the soft downy material from the underside of the leaves to line and plug their nests. Carder means to ‘tease out fibres’, and the female rolls the hairs into a ball as big as herself to carry home to her nest which is in a ready-made hole in dead wood, cavities in wall and man-made objects. I’ve yet to see one. You may also see the larger male bees aggressively defending their patch of purple flowers for mating by attacking intruders mid air. They are armed with spikes under their abdomen that can kill their foes. As well as Lamb’s ear, these bees can often be seen feeding or mating around Black horehound, Purple toadflax and vetches. NOTE: Despite having a similar English name to the Common carder bee (Bombus pascuorum), they are very different. The latter is a social bumblebee.
Bumblebee hoverfly (Merodon equestris) – some hoverflies are excellent bumblebee mimics with their fluffy coats and round bodies. TOP TIP: The way to tell them apart from real bumblebees is the eyes (flies have bigger eyes), the legs (flies have spindly legs and they don’t collect pollen on their back legs), and they tend to stay still on a flower or leaf for longer than a bee with their wings out, rather than tucked behind them.
How to help bees in June:
Planting different flowers for different bees is particularly important this month when there can often be what’s called a June gap in the UK – a lull in nectar and pollen supplies as the horse chestnut trees finish flowering and trees, such as the limes, have yet to begin while spring flowers fade before summer ones burst into bloom. Try cotoneaster and thistles for short-tongued bees, and foxgloves, honeysuckle, comfrey and catmint for longer-tongued bees like the Green-eyed flower bee. Research by bee-friendly plant supplier, Rosybee found that in June the yellow flowers of Dyer’s chamomile (Anthemis tinctoria) were the best for all types of solitary bees, followed by purple Geranium rozanne ( a favourite in my small garden because it flowers until October). Biennial Viper’s bugloss (Echium vulgare) was best for bumblebees, as it produces nectar all day long, followed by catmint (Nepta racemosa – another long flowerer) and a white lavender (Lavandula x intermedia ‘Edelweiss’). Don’t forget Lamb’s Ear (Stachys byzantina) for the Wool carder bees.
If you only have a window box, try growing Scabious japonica, dwarf harebells (Campanula carpatica), dwarf lavenders, Mexican fleabane (Erigeron karvinskianus), seaside daisy (Erigeron glaucus), and creeping thyme (Thymus serpyllum) which flower from June onwards. Water regularly.
Don’t pull up weeds like Alkanet, which feed many types of bees, and continue not to mow part of the lawn (after No Mow May comes Let it Bloom June ) to let clovers and knapweeds grow.
It’s not too late to install blue tit boxes – not for birds but for Tree bumblebees (Bombus hypnorum) and possibly Early bumblebees to nest in. They will vacate at the end of the summer, so you may get blue tits nesting next spring.
Put up bee hotels. It may be too late for Red mason bees, but Orange-vented mason bees, Blue mason bees and leafcutter bees may check-in and lay their eggs this summer. Leafcutter bees prefer slightly bigger diameter tubes of 9-10mm. The others 6-8mm. We have created flat-pack bee hotels that can be easily assembled and come with instructions about where to put them and how to attract bees to nest in them by planting their favourite flowers.
Create your own nests for cavity-nesting solitary bees, by drilling holes in blocks of wood – 10mm, 8mm, 6mm and 4mm diameters and up to 30 cm deep – and screw them to a sturdy support. Drill holes in existing structures such as fence posts, or dead trees. See which bees take up residence over the summer.
Continue to leave bare earth for mining bees to burrow into, or if you have space make a 1m 2 sand mound for mining bees to nest in. See here for a step by step guide.
Provide a source of water for thirsty honeybees. This can be a shallow bowl or saucer with stones or pebbles in that the bees can stand on while they are drinking. Bees can’t swim!
Ditch the weed killers and pesticides – that includes all bugsprays for your roses!
Where have the spring-flying solitary bees gone? The Hairy-footed flower bees (Anthophora plumipes) are disappearing, along with Red mason bees (Osmia bicornis) and early mining bees. This is because adult solitary bees only live for a few weeks (6-8 weeks). And the spring flying solitary bees that came out in April or before have now reproduced and provisioned their nests with pollen, so their life cycle has come to an end. In their short life they mate and then the female makes, or finds and adapts a nest in which to lay her eggs. She forages for pollen to leave in the nest for the hungry larvae which will hatch from her eggs and gobble up all the pollen. But she will never see her offspring. When she has laid all her eggs and provisioned them with pollen, she will plug up the entrance to the nest, and exhausted from all her activities she will die on the wing. But in her short life she has done an extremely important job – pollinated many flowers, shrubs and trees whose fruits, seeds and nuts are food for birds and other species. Once the larvae have eaten all the pollen, they spin a cocoon, pupate and transform into adult bees through metamorphosis. They overwinter in the cocoon and will emerge next spring to start the life cycle again. The males of all solitary bee species emerge first to build up their strength for mating. In the case of the Red mason bees, they break though the mud at the end of the tubes in the bee hotels.
Bee hotel and observation box in Memorial Garden, Guy’s campus, KCL, April 2025 – not enough flowering ground cover or shrubs
Science gallery, Guy’s campus – there are some flowering plants, but there needs to be more spring-flowering ground cover, bulbs and perennials, and a crab apple in the large pot.
Guy’s campus – non occupied bee hotels
Denmark Hill campus – too much bare earth and evergreen shrubs, needs bee-friendly groundcover, perennials and bulbs and shrubs like Rosemary (May 2025)
Stamford Street courtyard – shrubs cut back too much so can’t flower. Need to be underplanted with groundcover flowering plants such as geranium. Too many evergreens. No flowers for bees or other pollinators.
Great Dover Street courtyard – too much bare ground, nothing flowering. (May 2025)
GDS – Scope to plant up all the tree pits with spring-flowering bee-friendly bulbs and flowers
GDS – scope to replace dead Portuguese laurel with bee-friendly, evergreen Sweet box flowering January – March
Honor Oak – Bee hotel and boxes not occupied. Not enough flowers and a bit too shady. Could move to a sunnier spot (below) where the box and hotels could face south east and flowers could be planted.
Bee hotels are also situated in a shady spot in Maughan Library (below). There are no options for moving them to a sunnier spot, or to improve the flowering plants.
Cavity-nesting solitary bees have 3 requirements for nesting
1. Sufficient nectar and pollen-rich flowers when they are flying and looking to provision a nest with pollen
2. Suitable nesting boxes such as wooden bee hotels filled with 15cm deep tubes made of bamboo or cardboard, or wooden bee observation boxes. These should ideally face south or east, be a metre off the ground, in a fixed spot and undisturbed
3. Nesting material with which to construct their nests, such as damp earth (Red mason bees), leaves from Rose bushes (leafcutter bees), fibres of Lamb’s ear (Wool carder bee).
To date only requirement 2 had been met in most cases, but there is much planting that can be done to provide a variety of bee food and nesting material.
As World Bee Day approaches on 20 May, it’s good to look back at how Weil has supported bees over the past eight years. When Weil law firm approached Urban Bees eight years ago to find out how it could best help bees, we recommended that its south-facing terrace eight floors above Fetter Lane could provide an oasis for solitary bees, which are important, but often forgotten pollinators.
Improved forage: Urban Bees worked closely with the Weil gardener, Matt Bell, advising on flowers, shrubs and herbs to provide these wild bees with nutritious pollen and nectar from early spring to late summer.
Nesting sites: Then we installed and maintain bee hotels, thanks to the support of Margaret Lloyd, the then Weil Facilities Services Director, and now Rémy Chaugny, to provide safe nesting sites for solitary Red mason bees. These docile wild bees check into the hollow tubes contained in the cylinders and lay their eggs in early spring. See video here
Education: Staff have taken part in Urban Bees’ bee safaris on the terrace where they have identified different bee species on the flowers, learned how they can help bees at home, and have made ‘bee hotels’ to put up in their own garden.
And every summer, 30 pupils from Friars Primary School in Southwark – where Weil staff volunteer – visit the office to go on a bee safari with Urban Bees’ Alison Benjamin (pictured below) and a bee spotter guide. Alison also shows them how to make bee hotels to take home. Thanks to Sue Cook, Pro Bono & Corporate Responsibility Assistant, and Sarah Chase, Director of Research Services, for their help organising the school visit.
In 2022, Urban Bees added a bee observation box with removable panels (pictured below) to allow pupils and staff to be able to see the life cycle of the Red mason bees from egg, to larvae eating pollen, spinning a cocoon to pupate and become an adult bee the following spring.
“Urban Bees’ entertaining and practical lunchtime sessions about how to help bees have proved extremely popular with our employees at all levels of the firm. It’s been a fantastic way to engage employees in sustainability issues. Employees appreciate why Weil has transformed its roof terrace to provide food and lodging for wild bees. And pupils from one of our partner primary schools have come into the office to make bee hotels, gone on a rooftop bee safari with Alison Benjamin at Urban Bees and witnessed the life cycle of the bees. It’s an experience they say they’ll never forget!” Robert Powell, former Head of Pro Bono & CSR
In 2023, pollinator surveys on the Weil terrace over the summer recorded seven different species of bee;
Early bumblebee (Bombus pratorum) on thyme
Common carder bee (Bombus pascuorum) on St John’s wort (Hypericom)
2 x Yellow-face bees (Hylaeus) – a male (pictured below middle) and female Common yellow-face (Hylaeus communis) flying around the fennel
2 x furrow bees (pictured below left) – (Lasioglossum smeathmanellum) on hebe
Male leafcutter bee (Megachile centuncularis) on hebe.
Buff-tailed bumblebees (Bombus terrestris) on Jasmin and fennel
Honeybees on Buddleia, Jasmin and thyme.
The terrace scored an impressive 17/20 for providing habitat for pollinators. Surveyors commented: “A very good diversity and abundance of plants for forage and lifecycle stages.”And there are three small bee hotels on site and a bee observation box which are mostly occupied.”Dr. Konstantinos Tsiolis, leader of the Pollinating London Together surveys, (pictured above) hopes the Weil terrace could be an example for other City companies to follow. “It just goes to show how a small terrace in the City 8 storeys up that is used for entertaining clients in the summer can also be a haven for many species of wild bees by planting a diverse range of bee-friendly plants that are attractive to people and bees throughout the year”, he says. More on the Pollinating London Together 2023 Habitats Survey here.
Brown-banded carder bee (Bombus humilis) above left) In summer 2024, this rare bumblebee was recorded foraging on late-flowering lavender. It was the first recording by PLT in the City last year and was an important find. In the 2024 PLT Pollinator and Habitats Survey, the Weil rooftop was in the top 5 of all rooftops surveyed.
In spring and summer 2025, PLT conducted more surveys, Urban Bees ran its annual workshop for pupils of Friars primary school, and we continued to provide a haven for bees in the City without honeybee hives.
This month, hopefully you will see at least one new bumblebee species, a new mason bee, four types of mining bee, the now familiar Hairy-footed flower bee, and two ‘cuckoo’ bees – the Mourning bee and the Vestal cuckoo bee. (All photos credit: Penny Metal)
You will continue to see some of the bumblebees you first spotted in March and April, but instead of queens you will now probably be seeing the smaller worker bees foraging on flowering trees and plants.
How to ID May bumblebees:
Tree bumblebees(Bombus hypnorum) with their ginger thorax, black body and white tail could be the new occupants of your blue tit box if the chicks have fledged. I’ve not seen them in London for a few years now, so it appears you’re more likely to see them in cooler parts of the country. Be prepared for noisy buzzing outside their new home as gangs of males compete to mate with virgin queens. (As you can see from the photo, the male on top is much smaller than the queen.) Tree bumblebee colonies vacant a bird box at the end of the summer, so it will be empty for the blue tit family next spring. I still find it hard to tell Common carder bees (Bombus pascuorum) and Tree bumblebees apart when they are flying, despite the latter having a darker body and a white tail.
Top ID tip to tell a Common carder bee from a Tree bumblebee – both sport a bright ginger pile at this time of year (later in the year, the former fades and the latter goes a bit bald), so the best way to tell them apart now is to focus on getting a look at their bottom. The Tree bumblebee has a tiny white bottom and a darker body (abdomen). The Common carder bee is brown all over. Good luck!
Bumblebee cuckoo bee
Vestal cuckoo bee (Bombus vestalis) – also known as Southern cuckoo bee because she used to be more common in the south of England – looks very similar to a Buff-tailed bumblebee (Bombus terrestris). That’s because she resembles the bee whose nest she takes over. Like the cuckoo bird (hence the name), she lays her eggs in the nest already made by her host. The cuckoo bee will actually kill the host queen and her eggs and dupe the host’s worker bees into raising the cuckoo bee’s young. Cuckoo bees are either male or fertile females. They do not have queens or worker bees..
There aresix cuckoo bumblebees in the UK. Because Buff-tailed bumblebees are so common, so too is the Vestal cuckoo bee. Their presence means the host population is healthy.
Top tip for telling a Vestal cuckoo bee from a Buff-tailed bumblebee – The easiest way to tell these two large bumblebees apart is that the cuckoo has a longer white tail and above the tail is a pale yellow band. It’s a paler yellow than the dirty gold on the bee’s thorax and paler than the Buff-tailed bumblebee’s golden bands. The Vestal cuckoo female is a similar size to a Buff-tailed bumblebee queen but much bigger than Buff-tailed workers. Their wings may seem a bit darker and the other tell-tale is that they never carry pollen (as the host workers will feed its young). This is true for all cuckoo bumblebees.
How to help bumblebees in May:
Leave a patch of the garden wild for nesting sites and don’t disturb a nesting site if you find one for example in a compost bin or under a garden shed (it will only last until the end of the summer). Leave some permanent long grass in which Common carder bees may nest.
It’s not too late to put up a blue tit box for the tree bumblebee to nest in. Again, they will leave at the end of the summer and birds can use it next spring.
Buy and plant alliums, catmint and cotoneaster from garden centres to provide food this month for short-tongued bumblebees. Foxgloves, honeysuckles and thistles for the long tongued bumblebees.
It’s not too late to grow from seed annuals that provide late summer bee forage such as sunflowers, cosmos and Anise hyssop.
Scatter wildflower seeds or seed balls in pots or on bare earth. The annuals will flower later in the summer and perennials next year.
How to ID May solitary bees:
Grey-patched mining bee (Andrena nitida) is one of the most common mining bees in southern Britain, extending up to Lancashire and Yorkshire. She has a brighter red, fluffy pile on her thorax than the short-fringed mining bee, and grey patches on her black abdomen. These medium-sized bees (10-12mm) can be found foraging on spring blossoming shrubs and trees and dandelions and in scattered nests in flat or sloping turf and lawns.
Top tip for finding a Grey-patched mining bee – find it’s more striking waspish-looking Nomad bee, (another name for a cuckoo), Flavous nomad bee (Nomada flava). You can see them on the ground searching out a Grey-patched mining bees’ nest to take over, and then you may spot the host bee herself.
The short-fringed mining bee (Andrena dorsata) is widespread too in southern England. Sporting a reddish-brown fluffy pile on her thorax, a smooth black body with thin stripes, and a very hairy dorsal fringe on the top of her back leg, the female should hopefully be easier to identify on dandelions and daisies than some of the other small, brown mining bees also around at this time of year.
Hairy-footed flower bees (Anthophora plumipes) have been flying for a couple of months now so you are probably becoming accustomed to seeing them darting noisily around patches of comfrey and wallflowers with their tongues outstretched. Many of the black females will have mated and are now busy collecting pollen on their hairy hind legs for their young.
Ashy mining bees (Andrena cineraria) A distinctive black and grey stripped bee (around 11-14mm), which nests in bare ground, footpaths and tracks. Although solitary, they nest next door to each other in dense aggregations, so hundreds can emerge at the same time. But don’t worry, solitary bees don’t sting and are short-lived (around 2 months)!
The Mourning bee(Melecta albifrons) is another black and grey bee. Her coat is a fluffy grey/black colour, edged with lateral white spots. Despite her cute appearance, these are the Hairy-footed flower bees’ cuckoo. The female lays her eggs in the already made nest and when her larvae hatch they steal the pollen collected by the Hairy-footed flower bee. A quarter of the 20,000 plus bee species on the planet are cuckoos.
Top tip for telling a Mourning bee from an Ashy mining bee – the former is rounder and fluffier, like its host bee, and also has lateral whitish spots down its body. The Ashy mining bee has a longer, smoother black body and is often found near to the ground nesting in large aggregations.
Common mini-miner (Andrena minutula). If you see a tiny mining bee (4-5mm) at this time of year, chances are it will be this mini-miner bee because as its name suggests it’s the most common of the 10 species of mini-miners in the UK. They have a hairy fringe along the thorax and markings on their head if you can get that close. They are most visible on dandelion type flowers and sallow (willows). They nest in loose soil in large groups.
Blue mason bee (Osmia caerulescens) – bit smaller than the more common Red mason bees, the males, which are flying now, have a fluffy brown pile of hair over a dark metallic-coloured body. The females look blueish-black with a box-shaped head. They will nest in manmade bee hotels, but construct the cells and plug the tubes with chewed pieces of leaf. You may see them on a variety of flowers in an urban garden. The females come out a week or so after the males and they are around until July.
How to help solitary bees in May:
Plant wallflowers and comfrey for long-tongued Hairy-footed flower bees. Flowering fruit trees, willows, spurges, alkanet and forget-me-nots and geraniums for Red mason bees, and mining bees.
Leave old mortar untouched as Hairy-footed flower bees and Red mason bees may be nesting here.
It’s not too late to make cob bricks with holes in that Hairy-footed flower bees may nest in. See how to make them with clay soil, builders’ sand, straw and water in this wonderful video by ecologist John Walters.
It’s not too late to install bee hotels in a warm location at least a metre off the ground, where Red mason bees can check-in and lay their eggs. We like to use these flat-pack bee hotels we have made, filled with either cardboard tubes or bamboo tubes that are 150mm long and around 5mm in diameter.
Leave a patch of bare earth for mining bees to burrow.
Leave a patch of bare, wet earth for Red mason bees to collect mud to make partition walls in the tubes where they are nesting and to plug the end of the tubes.
Don’t mow the lawn to let dandelions and clovers grow. Small, brown mining bees are easiest to see on bright yellow dandelions. I now let dandelions grow in my herbaceous perennial flower borders to spot these bees.
The rooftop garden at Bow Bells House in Bread Street, was found to be the third best rooftop garden for pollinators in the City in 2024 and the six best greenspace for pollinators out of all the private gardens surveyed in the square mile by ecologist Dr Konstantinos Tsiolis for the charity Pollinating London Together.
The result is a vindication of the important role roof gardens have to play in providing habitat to pollinators in urban areas. Moreover, it belies the notion that bees and other pollinators will not forage and possibly nest above a certain height. Bow Bells House garden is high up on the eighth storey. There are advantages to being high up, notably that unlike many ground floor gardens in the City, it is unlikely to be shaded by a tall building. Since pollinators are cold-blooded and need sunlight to warm up and create the energy to power their flight muscles, they prefer to forage on sunny rooftops than shaded courtyards.
Each garden or greenspace was scored against the following critera:
the value of plants as forage for pollinators throughout their lifecycle stages
suitable and well maintained nesting resources
pesticide use
monitoring
number of pollinator species/groups found.
Bow Bells House scored scored highly for:
a good diversity and abundance of plants for forage throughout the year
three small bee hotels mostly occupied
no pesticide use
regular monitoring
15 different pollinators recorded on site during monthly visits in the summer, including Green furrow bees (Lasioglossum morio), Four-banded flower bee (Anthophora quadrimaculata), Wool carder bees (Anthidium manicatum), Red mason bees (Osmia bicornis) and a number of hoverflies, a drone fly and a cabbage white butterfly.
Steps to success
I’ve created and maintained the two large planters on Bow Bells House for a few years now for Savills, which managed the office block. I was first invited to take over the maintenance of the planters and to improve the planting for bees in 2021. We added 2 bee hotels for Red Mason bees in 2023 after the bee-friendly planting was established and honeybee hives had been removed.
These are are number of reasons why I think the garden is such a hit with pollinators:
Unlike many rooftops it is not used for any other purpose other than pollinator habitat so it doesn’t have to look neat and tidy or to be landscaped. (That is not to say that a neat, landscaped roof-garden can’t be just as good for bees, but it has allowed us to experiment more).
I’ve been able to experiment with different plants to see which thrive in the conditions and provide the best forage for pollinators
I have allowed ‘weeds’ that have self-seeded to grow if they provide food for pollinators, such as gorse and thistles
I have prevented certain plants and ‘weeds’ from dominating – this takes hard work and time
It has a timed irrigation system so plants thrive even in drought conditions (before the irrigation system was installed we lost plants because the shallow depth of the planters means the soil dries out very quickly)
Honeybee hives were removed a few years ago so that other pollinators could forage without so much competition (however there are hives nearby so there is still a preponderance of honeybees foraging on the roof).
In total 23 greenspaces in the City were scored for their effectiveness for pollinators in between May – September 2024. Of these, 10 were rooftops.
The full report of of the Greenspace Habitat Survey 2024 will be available next month.
We saw some amazing bees in Costa Rica between December 2024 – February 2025. They have over 700 species, but unfortunately due to wet conditions and colder than average temperatures in some areas, and the fact that in the jungle all the flowers are at the top of the tree canopy, we didn’t see a huge number. But those we did see included:
Metallic green orchid bee (Euglossa) collecting fragrance from a patch of Peace Lilies (Spathiphyllum canniflium) in a famous botanical gardens. The bee is a male collecting fragrance from the plant with which he will woo a female bee. He stores the fragrant oils inside his hind legs and disperses them with his wings during courtship. And the females are seduced by the wafts of perfume, or just impressed by how many different scents the male has managed to collect. No one knows for sure. This means, that unlike males in most bee groups, make orchid bees are important pollinators when they are collecting the fragrances. There are some 40 species of Euglossa in Costa Rica. We were hoping to see more green ones, and metallic blue, red, purple and copper ones. They are around 10-15mm long, so easy to see. Unfortunately the only other ones we saw were at the University of Costa Rica bee collection.
Eulaema cingulata – until I visited Costa Rica I thought all orchid bees were small and metallic coloured, and only foraged on orchids. But they can also be big and fluffy like this one below which is around 28mm long, and looks like a bumblebee with a long body and collects pollen in baskets on its hind legs. Its collecting fragrance from the Peace Lily and pollen and nectar from Stachytarpheta frantzil, a purple flower popular with all pollinators including humming birds.
Mesoamerican bumblebee (Bombus ephippiatus), is one of only seven bumblebee species in Costa Rica. They can only live in the country’s cooler mountainous areas (above 1600 metres). They nest underground in abandoned rodent nests like UK bumblebees, which is perhaps why we saw this one is on the ground. She is the size of a Buff-tailed bumblebee, but looks like she is wearing fluffy, cream-coloured shoulder pads.
Tetragonisca angustula are one of 54 species of stingless bee in Costa Rica. They live in colonies like honeybees – but only about 10,000 of them – and make wax and honey. They don’t sting, but if threatened can bite with their mandibles. Some species are more aggressive than others. Luckily these little orange bees, 4mm long, were harmless as their nest was in the wall cavity of a cabin where we were staying for a week. They made the tube entrance to the nest from resin and wax. It was fascinating to watch them building and adapting it.
Lemon bees (Lestrimelita) are a species of 6mm long, glossy black, stingless bee that rob pollen from other stingless colonies. They get their name from the citrus smell they emit. When they are plundering a nest they release chemicals that overcome the host colony. Their own nest is an odd, rather ugly, irregular structure of wax and resin that sticks out of a tree cavity. These bees can be quite aggressive if people come too near to the entrance of their nest.
Centris bees number around 250 species in Costa Rica. We saw two: one, which hovered and looked similar to a Hairy-footed flower bee, making a nest in a wooden bee hotel; the other which we think is a Centris flavofasciata was making a nest in the sand on a beach. She reminded me of a Pantaloon bee (Dasypoda hirtipes) as she had the same oversized brushes on her hind legs.
Many thanks to the authors of Bees of Costa Rica for teaching us about the the country’s rich bee biodiversity. In particular, Prof Paul Hanson (pictured in blue shirt below) for showing us the bee collection at the University of Costa Rica.
And Mariana Acuna Cordero (below left) for meeting us in San Jose and helping to identify many of the bees we saw during our travels, and Gordon W Frankie, professor emeritus at the University of California in Berkeley, (second left) who put me and Brian in touch with Paul and Mariana and who we were lucky enough to meet by chance with Mariana at the incredibly hot Palo Verde National Park and research station the end of our travels.
If you’re new to bee spotting, now is the month when you can really begin. If you’ve been waiting all winter to get back to bee spotting, now’s the time to resume on dry, sunny days.
In March you could see three species ofbumblebee:
The Early bumblebee (Bombus pratorum) queen is smaller (14mm) and prettier than the Buff-tailed bumblebee (which you may have seen flying over winter). The Early bumblebee queen has a fluffy yellow collar and orangey bottom.
The Common carder bee (Bombus pascuorum) The queen bumblebees are collecting (cardering) bits of moss to line their nest which they make above ground in undisturbed areas at the bottom of gardens. They also need nectar to fuel their flight after a long period of hibernation. Their long tongue, means you are likely to see them foraging on dead-nettles at this time of year.
(You will also likely see big Buff-tailed bumblebees this month as they are our most common bee with their golden stripes and whitish tails)
Six solitary bee species:
Hairy-footed flower bees (Anthophora plumipes) are often mistaken for bumblebees because of their round, fluffy appearance, but they live alone (not in colonies). The brown, male Hairy-footed flower bees is starting to emerge in some warmer parts of the country and bigger, black females will soon follow. But most of us will have to wait a bit longer to see both of them. They visit Pulmonaria (lungwort) and other flowers with bell-shaped flowers. The males suck up the nectar with their long, straw-like tongues (proboscis) to build up their energy for mating when the females appear. A male will often jealously guard a patch of flowers where he hopes to get lucky, and chase off other potential suitors. More than one male can often be seen in pursuit of a female.
Buffish mining bee (Adrena nigroaenea) is one of our most common garden mining bees widespread across England. Around the size of a honeybee but a bit stockier, this 10-11mm-long bee has a dense fluffy brown pile on the top of its thorax. It can be tricky to identify from other brown bees. It nests in footpaths, flowerbeds and lawns. Although solitary, these bees nest next door to each other in large groups. Like all solitary bees, the males appear a couple of weeks before the females.
Male Red mason bees(Osmia bicornis) can emerge towards the end of the month to feed on blossoming fruit trees and shrubs. If you have a bee hotel you may see these cavity nesting bees checking out of the mud-plugged tubes. They eat their way out. The male eggs are laid at the front of the tubes making it easier for them to emerge earlier than the females. They are a little smaller (6 – 8mm) than a honey bee (9-10mm), more gingery and have a rounder bottom.
Male Orange-tailed mining bees (Andrena haemorrhoa) are a little smaller (8-11mm) and less robust than Buffish mining bees. The smaller males have buff on their face and a brown pile on the thorax and at the tip of their tail. Their name derives from the larger females (which may not be out until April) which have an orange-tipped tail. They took up residence one summer in our Bee Observation Box, which I will put up next month.
Gwynne’s mining bee(Andrena bicolor) is a bit harder to spot, being 7-11mm, but look down and you may see them burrowing through soil on south-facing banks. Although solitary, they nest next door to each other underground in aggregations, so hundreds could emerge at the same time. But don’t worry, solitary bees don’t sting! The female has a reddish-brown pile on the top of her thorax and hairy pollen brushes on her back legs. The males are much blacker and shinier. They seem to forage on most spring flowers and as such are seen throughout England and Wales.
Common mini-miner (Andrena minutula). If you see a tiny mining bee (4-5mm) at this time of year, chances are it will be this male mini-miner bee because as its name suggests it’s the most common of the 10 species of mini-miners in the UK. They have a hair fringe along the thorax and marking on their head if you can get that close. They are most visible on dandelion type flowers and sallow (willows). They nest in loose soil in large groups.
Bee mimic of the month:
Many people confuse the Dark-edgedbee-fly(Bombylius major) for a bee (which is why we’ve included it). Not surprising there is confusion, because it’s a great mimic – round and fluffy like a small bumblebee (14mm long). It’s an example of Batesian mimicry which involves a harmless species mimicking a harmful one to avoid predation. This Bombylius is very visible in the spring, hovering around green alkanet and wallflowers. The easiest way to tell it apart from a bee is its long, spindly legs, its large eyes and it has two wings (bees have four wings) which stick out at a 45c angle when it rests, whereas bees usually stick their wings behind them.
The honey bee (Apis mellifera) workers (14mm) leave the hive when its 13c. Shaped like a wasp, they have black and amber stripes. Look up and you will see them high up on fruit trees, pussy willows and hazel and alder collecting nectar and pollen to take home to feed their queen and thousands of hungry larvae that will develop into workers and drones. (We’ve not included them in our Bees to See in March guide above as we wish to raise awareness about solitary bees and bumblebees).
How to help bees this month:
Gardening for bumblebees:
Leave a patch of the garden wild for nesting sites and don’t disturb a nesting site if you find one in a compost bin, under a shed, or even in a watering can (it will only last until the end of the summer).
Put up a box for blue tits. After the chicks have fledged, the box may be inhabited by Tree bumblebees (Bombus hypnorum). The colony will vacant at the end of summer, so the blue tits can use it again next spring.
Plant primroses, Forget- me-nots, Rosemary and heathers to provide food this month for short-tongued bumblebees.
Longer-tongued bumblebees like Common carder bees prefer dead-nettles and wallflowers.
Leave ‘weeds’ like dandelions and alkanet to grow. They provide much-needed pollen and nectar in early spring. And you’ll see lots of different bees coming to feed on a clump of alkanet.
Sow seeds inside now to create more flowers later in the summer. Sweet peas, sunflowers, cosmos and Anise hyssop are some of the easiest to grow in pots. Try growing on a heated mat until the seeds germinate. I’m also going to try Chives, Viper’s bugloss and cornflowers outside next month.
Instead of seeds, you can buy bee-friendly plug plants that are quicker to establish. My favourites are stocked by Rosybee.
Don’t mow the lawn to let clovers flower.
Ditch the weed killers, like Round-up, and any pesticides and bug sprays you may be using on your roses, or any other plants.
Gardening for solitary bees:
Plant lungwort, wallflowers, dead-nettles, early-flowering comfrey and flowering currants (Ribes) for long-tongued Hairy footed flower bees. Red mason bees and mining bees, with shorter tongues prefer flowering fruit trees, willows, spurges, alkanet and forget-me-nots.
Leave old mortar untouched as Hairy-footed flower bees may be nesting here.
Make cob bricks with holes in that Hairy-footed flower bees could nest in instead.
When the weather is dry and warming up a bit, I install bee-hotels in a warm location at least a metre off the ground, where Red mason bees (Osmia bicornis) can check-in and lay their eggs. We’ve designed our own wooden bee hotels which we stuff with cardboard tubes.
Leave a patch of bare earth for mining bees to burrow and nest, and where Red mason bees can collect soil to plug their nests.
If you see bees coming up through your lawn, just leave them. They are a harmless mining bees emerging in spring to pollinate your garden flora.
Don’t mow the lawn to let the mining bees emerge and to nest, and to let dandelions flower.
Ditch the weed killers, like Round-up, and any pesticides and bug sprays you may be using on your roses, or any other plants. Leafcutter bees depend on the leaves of rose bushes to construct their nests.
November is a good month to take apart a bee observation box in order to clean it out and store the bee cocoons in a clean, dry cardboard box in a shed over winter. I do this, so that next spring the new generation of bees will have nice, clean channels to nest in.
Here are some easy steps to cleaning out your box. It can get quite messy, so wear your gardening clothes. You’ll need an:
old table cloth
small screw driver
thin, metal skewer
small brush
cardboard boxes
washing up liquid, only to clean the Perspex cover.
Step1: Remove the insert from its exterior wooden box exterior and put it on a table covered in a white cloth. Do this in a cool area, like a shed or on a garden table.
Step 2: Remove the small screws that holds the Perspex – revealing a clearer view of the cocoons in their mud partitioned cells or nurseries.
Step 3: Carefully (I use a metal kebab skewer) get under the cocoons and scrape out the content of each channel – flaky mud, hard pollen, delicate cocoons and flecks of poo.
Step 4: Place the smaller, male cocoons at the front of the channels on one side of your white sheet and the large female cocoons at the back of the channels on the other side if you wish to store them separately. (Remember mum always lays male eggs at the front of the nest and females at the back so the males can emerge earlier in the spring).
Step 5: Take each cocoon and gently brush the flecks of poo off with a soft brush, like a paint brush or make-up brush and place in a cardboard box. I’ve lined mine with newspaper and separated what I think are the boys from the girls.
Step 6: Clearly label the box. We have a number or bee boxes that we manage for clients and are cleaning out this winter, so we’ve also put the name of the client on the box too. Close the box and put in a dry, cool place.
Step 7: Now, clean out the channels as best you can. Get as much as the debris out as you can with the skewer and then with a brush. It’s best NOT to use a damp cloth as the water could make the wood expand. The channels don’t have to be perfectly clean, just rid of poo, old pollen, any larvae that didn’t develop into a cocoon and may harbour disease, and any unwanted pests and parasites that may have laid their eggs in the channels too.
Step 8: Clean the Perspex cover with washing up liquid and a scrubber. Dry. Then screw back onto the wooden channels. (Photo to come). Store in a dry place over winter. Dispose of the debris in your compost bin.
Finally this summer (2024), the 5 planters on the 5th floor terrace of an office opposite the Barbican finally sprung into life thanks to an irrigation system. Before it was fitted (it took a year to get it agreed and an outside tap fitted etc), the planters always looked rather sad and nothing grew well in the two very shallow ones. But the plants listed above are all now thriving and feeding passing bees in succession from early spring to late summer.
I even managed to get some photos of Common carder bees (Bombus pascuorum) on the lavender x ‘Grosso’ and Red clover in August.
This is the sorry sight in March before the watering system was installed. It is a drip system and receives 5 minutes of water every 12 hours (on top of any rain that falls). Even though we’ve had a wet spring/summer, there have been long periods without rain when the planters can dry out very quickly, so the plants conserve their nectar leaving less for hungry pollinators to consume.
Although it’s not clear from this photo, we do have Red mason bees (Osmia bicornis) nesting in the two bee hotels attached to the planters by a metal pole. In spring, the Rosemary will feed them.
I’m always keeping my eyes out for good late planting for bees in London. I’m happy to say it’s in abundance around St Paul’s cathedral and King’s Cross this August and September. Above is a plot bursting with Lily turf (Liriope muscari) and Japanese anemone (Anemone x hybrida) in pink and white. If you prefer more fiery colours for late boarders there are plenty of bee-friendly flowers to choose from.
Hot orange dahlias and Cosmos sulphureus – a new Cosmos for me – attract the bumblebees in front of St Paul’s, and swaths of Rudbekia are visited by solitary bees and hoverflies.
Masses of asters that flower much earlier than the traditional Michaelmas daises; and Buff-tailed bumblebees enjoying the nectar and pollen from these single-headed dahlias.
Beautiful landscape planting that’s attractive for people and pollinators in late summer/autumn and hopefully all year in a shady corner. Can’t wait to see what it looks like in spring.
As it’s been such a poor season for bees in my garden and rooftops, I’m just pleased to see Common carder bees (Bombus pascuorum) finally out in force. One of our most common bumblebee species, it has been noticeably absent for most of the summer, so it’s gratifying to see these small brown fluffy bees foraging on late-flowering lavender, salvia and toadflax. What’s even more encouraging is spotting large bumblebee queens and males (which in some species look different to workers and queens). The males are looking for new queens to mate with, and the new queens, once mated, are stocking up on nectar to build up their fat reserves when they hunker down over winter. A colony that’s produced lots of queens and males is a success story.
As for solitary bees, many of the more charismatic species have completed their adult stage, but if you’re anywhere near sandy banks, look out for Pantaloon bees which are still nesting. Elsewhere, small, black solitary bees are still foraging, including Common furrow bees – easier to spot than the more diminutive Green furrow bee – and Large-headed resin bees. And there have already been reports of male Ivy bees emerging. More about that below…
Tips for IDing September bumblebees:
Red-tailed bumblebees (Bombus lapidarius) – increasingly rare in London, but easily recognisable when you do get a glimpse. The males, (12-14mm) which are flying now are one of our prettiest bees with their yellow facial hair and red bottoms. The queens are much more dramatic, dressed in black with a fiery red butt. In the south, queens can produce a second colony of up to 300 bees, so it’s this second generation there are now flying. The queen is one of our biggest bumblebees: measuring 20-22mm. Workers are a smaller version of the queen (14-16mm). They have been spotted them on chives and alliums. I’ve heard they like yellow flowers, and last year I did see one on the yellow vetch, Bird’s-foot trefoil (Lotus corniculatus), on the 11th floor of an office block in central London!
Tree bumblebees(Bombus hypnorum) – if you’ve been bee spotting all summer, you may be quite adept at identifying tree bumblebees by now with their ginger thorax, black abdomen and white tails. Perhaps you’ve even had them nesting in a bird box in your garden. However, I’ve not seen one all year, again! They seem to have disappeared from London but are doing well further north. Is it too hot for it down here now? They usually have two generations each summer so if you see any flying this month they will likely be new queens, workers and males from the second 150-strong colony. The only difference in appearance between the queen, males and workers (known as the three castes) is their size. Queens are a larger 14-20mm, males 11-13mm and workers 13-15mm.
Common carder bees(Bombus pascuorum) live up to their common name at this time of year by being frequent garden visitors. Queens are now producing new queens, which are a sizeably bigger than the 11- 13mm workers. Both castes will be foraging, alongside males too. The castes all have the same ginger pile on their thorax, but the queens and males’ will be more striking as the workers’ colouring fades with age to a light brown. They are the smallest bumblebees flying in September.
Other bumblebees you’re likely to see this month are Buff-tailed bumblebees (Bombus terrestris). This month huge mated queens (18mm) are flying, as well as workers and males. In the south these queens are stocking up on nectar and looking for a suitable nesting site to raise a new colony during the mild winter. Further north, the queens are stocking up on nectar and looking for a suitable place to overwinter.
How to ID September solitary bees:
Pantaloon bee (Dasypoda hirtipes) – I always associate this sand-loving mining bee (13mm in length) with beaches because of the way the female uses her large, rather comical oversized pollen brushes on her hind legs, known as ;pantaloons’ to dig a hole for nesting in coastal dunes. But she is just as happy on sandy brownfield sites in mainly southern England and Wales. Her nest can be distinguished from other burrowing bees by the large fan of sandy spoil she leaves to one of side of the hole. You can see how she makes her nest in this great video. The males don’t sport the ‘pantaloons’ but still have long fair hairs on their hind legs.
Ivy bee (Colletes hederae) – one of the highlights of autumn is being able to spot an ivy mining bee. To the untrained eye, they can look deceptively like a honeybee, especially as they are both found en masse buzzing around nectar-rich ivy flowers. However, look closely and you’ll see the ivy bee has more hair on its thorax and its body has much more defined and shiny segmented bands in buff and brown alternate colours. The males, which are out a couple of weeks before the females, sports a brown quiff and are a little smaller (8-9mm) than honeybees (10mm). Despite their name, Ivy bees can gather nectar (and the females pollen) from a variety of late flowers before the ivy flowers, but the easiest way to spot them is to inspect the tiny white ivy flowers. Ivy bees belongs to the Colletes family, which mine into the ground to make their nests – often next door to each other in very large numbers – and they line their nest with a cellophane-like waterproof and fungus-resistant substance, which is why Colletes are also called plasterer bees. If you have a south-facing slope with light soil you may see hundreds, even thousands, of these bees emerging from their individual nests. It is easy to forget that they are solitary bees, ass you can see on thisgreat video from the Hampshire & Isle of Wight Wildlife Trust.
Fascinating fact – the Ivy bee was only described as a separate species in 1993 and wasn’t discovered in the UK until 2001 in Dorset. Unlike the other newcomer, the Tree bumblebee, Ivy bees aren’t thought to have spread to the north of England. But if you see one beyond the Midlands, please report your sighting to BWARS (Bees, Wasps and Ants Recording Society).
Common furrow bee(Lasioglossum calceatum) – these small solitary bees (8-10mm) with an elongated black shiny body have been flying since early spring. So there is no excuse for not recognising them in daisies and geranium flowers. The ones you will be seeing now are males and females that were born in July and can fly until October. They makes nests in the ground.
Green furrow bee(Lasioglossum morio) – an even smaller (4-5mm), black solitary bee, this one has a green metallic hue. But you can only really see this if you have a net to catch the bee and put it into a glass tube and then study it with an eye glass. I’m still not confident catching bees in a net, but I’ve been fortunate enough to go out a few times with an ecologist who is. And I got to see some of these bees close up in a tube and could clearly see the green. They are widespread and we’ve found them a number of times eight floors up on London rooftops foraging on hebes and a wildflower called Hoary willowherb (Epilobium parviflorum).
Fascinating fact: Both of these burrowing, furrow bees can display primitively eusocial behaviour, which means the early flying females in warm climates are actually queen bees that in early summer produce workers. These worker bees will collect nectar and pollen for the new females and males that are born later in the summer.
Large-headed resin bees(Heriades truncorum) – another small (8mm), black, robust bee often seen at this time of year in the south of England on yellow composite flowers like sunflowers. The easiest way to distinguish it from other small, black bees is that it carries pollen on the underside of its abdomen (like a leafcutter). And it make its nest in a pre-existing cavity in wood. After she has laid her eggs in the cavity, she plugs it with tiny bits of grit and stone that she collects and then glues it all together with resin collected from nearby trees. You can help this bee by drilling holes into wooden logs and attaching them to a wall. See how to make a nest for this bee.
Fascinating fact: She is found in Europe and the east coast of the United States and is thought to have possibly been introduced in the UK by Victorians in imported wood )
Another solitary bee you may still see this month is the tiny Common yellow-faced bee (Hylaeus communis) – these small (5-7mm) predominately black bees with tiny yellow eye spots (female) or a triangle (male) on their face has been a familiar sight in gardens since mid summer (if you’ve been able to spot such a diminutive bee). They plaster their nests, but unlike other bees collect pollen in a special stomach, called a crop, and regurgitate it to make a semi-liquid mixed with pollen to feed the larvae.
Fascinating fact: They have been observed blowing bubbles of nectar to evaporate the water. This is known as water homeostasis and it concentrates and thickens the nectar/pollen mixture making it tacky like honey. The bee’s eggs and larvae ‘stick’ to its surface, unlike many other solitary bee larvae which ‘sit’ on top of the more solid pollen mixture. Here is a video of the bubble blowing. (Thanks to Nurturing Nature and Api:Cultural for the info and footage).
How to help bees in September
Plant flowers that bloom this month to provide important late sources of nectar and pollen. Sedum, Michaelmas daisy, dahlia, fuchsia, Devil’s bit scabious, Coreopsis (Tickseed) Perovskia Blue Spire, commonly known as Russian sage, and wild marjoram (Origanum) are all good, and don’t forget Common sneezeweed (Helenium autumnale), the solitary bees favourite, according to Rosybee nursery’s fantastically helpful research . A particular fav in our garden was Helianthus ‘Lemon Queen’ a slug-proof sunflower, and of course, the Geranium Rozanne is still going strong! For the long-tongued bumblebees, black horehound, salvias, and buddleia are still flowering.
The best late forage for short-tongued honeybees and Ivy bees without a doubt is ivy. But ivy only flowers when it is mature and that can take 11 years! So if you have any sprawling ivy that needs a trim, please don’t cut it back until after it’s flowered this month.
If you only have a window box, Mexican fleabane (Erigeron karvinskianus), trailing nasturtium and Bird’s-foot trefoil are still flowering. Add sedum and annuals such as cosmos and snap dragons. If you grow herbs in pots and window boxes, let the mint and oregano keep flowering.
Gather seeds Store them in labelled paper bags in a cool, dry place for sowing or scattering next spring. Or, just scatter them around your garden now while the soil is still warm. Lightly rake the soil, scatter the seeds, cover them with fine soil and firm down.
Leave parts of the garden undisturbed, as ground nesting bumblebee queens may be looking for a snug place to overwinter – and don’t chop down old, dead stems that solitary bees may have laid eggs in.
Boost your wildflower meadow . If you haven’t already done your summer cut, do it now, scarify the cut meadow to expose bare soil where seeds can grown, then add yellow rattle seeds to suppress grasses taking over next year. Finally, add perennial plug plants of wild flowers that will grow well in the soil to feed bees in the future.
Ditch the weed killers and pesticides.
Takesemi-ripe cuttings if you are patient and want to propagate heathers, ivy, Mahonia, Escallonia, flowering-currents, verbena, penstemon and salvias. The cuttings should be ready to pot on next spring.
Create a bank of sandmixed with some clay soil against a south facing wall, or a free-standing mound, for mining bees which like to burrow into sand. It needs to be about 400mm deep. Create steps in the sand as some bees like to nest vertically and others horizontally. The clay will help the bank to keeps its shape after the bees have tunnelled into it. If you’re lucky you may get ivy mining bees nesting in it this autumn next door to each other in large neighbourhoods.
Drill holes in blocks of wood – 10mm, 8mm, 6mm and 4mm diameters and up to 30 cm deep (although some bees only need a depth of a few centimetres to nest in) – and screw them to a sturdy support. Drill holes in existing structures such as fence posts, or dead trees. Large-headed resin bees, scissor bees and yellow-faced bees may take up residence, but probably not until next year.
A new client wanted five planters located on the third floor roof of their Clerkenwell office in central London. The roof was already covered in a sedum mat which had looked dead when we first visited in February, but when we came to do the install in June (the project had been delayed), the sedum mat was blooming! So we placed four 500mm x 500mm x 280mm wooden hexagonal planters on the four corners of the sedum mat to avoid disturbing existing bee-friendly flowers.
We filled the planters with long-flowering perennials as to feed a variety of bee species in late summer, and installed a drip irrigation system in case of a drought. On our first maintenance visit at the end of July, we were surprised to see so many bees.
On the yellow, peak-like flowers of Bird’s-foot trefoil trailing at the back of the planters we saw Common carder bees (Bombus pascuorum), on the purple Campanula flowers we saw tiny, black Yellow-face bees (Hylaeus) and the Furrow bees (Lasioglossum) with their longer, banded abdomen. We also saw the Furrow bees on the white daises of Erigeron karvinskianus.
The tall purple spires of Veronica attracted both Buff-tailed bumblebees (Bombus terrestris) and many small, black solitary bees which I couldn’t get a good photo of, so I’m not sure if they were also Furrow bees and Yellow-face bees.
In the autumn we will plant up the planters with Crocus and Grape hyacinth (Muscari armeniacum) bulbs for early flying bumblebees and Hairy-footed flower bees.
We will add a fifth, slightly larger planter in the middle of the sedum mat and fill with Rosemary and Wallflowers (Erysimum) to feed spring-flying solitary bees.
In spring 2025, we will also install bee hotels for cavity-nesting solitary bees to nest in, and maybe an observation box if employees are interested in discovering the lifecycle of solitary bees nesting on their office.
I made a beeline for Gold medal winner Buglife’s B-Lines Garden to get some ideas for creating a small, urban bee paradise, including the attractive wooden bee towers. I also loved some of the tiny spaces designed by newly qualified garden designers, like Brian Bloodglut (pictured with me above) to demonstrate the scope of the Asteraceae family of flowering plants, including his Brian &the Blooms For the Birds garden. It’s amazing how many different Asteraceae he has crammed into such a tiny space. And the Flower Power Field below (right) was cool too, The Pollen Station in the Money Saving Garden was a reminder how important it is to vote for Nature in a General Election, which was the day after my visit.
I wasn’t the only one who loved the Making Sense Garden, above left. It won the People’s Choice Award for best Get Started Gardens.
Discovered a new flower in the Buglife garden – an African thistle (Berkheya purpurea) and I love the way that Kent Wildflower Seeds plant wildflowers, like Bird’s-foot trefoil and Clover, in pots we you would an ornamental plant.
Due to the dismal drizzle and cold, few bees were foraging on the lovely flower displays. However I did come across a lovely metal sculpture of a bumblebee, and some fun bees created by Manor Park primary school along with barrels filled with bee-friendly plants.
For all the information about the show winners, trends and plants here
Dr Konstantinos Tsiolis is searching for signs of Wool Carder bees (Anthidium manicatum) nesting in this park bench in Christchurch Greyfriars Garden, in the City of London, near to St Paul’s Cathedral.
The hunt was carried out in June 2024 during a pollinator survey for Pollinating London Together. Konstantinos had mentioned to me that he’d found the bees nesting there in 2022, so I suggested we see if they are still using it.
Wool carder bees like to nest in cavities in wood, so it makes sense that in an urban environment they would look for an existing hole in manmade wooden structures like a park bench. Once they’ve found a suitable dark, dry cavity with enough space to lay a few dozen eggs, they need to collect fibres from specific plants to cram into the nest on which to lay their eggs. Their favourite is the soft fibres from the leaves of the Lamb’s ear plant. Below we can see the opening of the rectangular hole under the arm of the bench has been plugged with what appears to be Lamb’s ear fibres.
We didn’t actually see any bees coming and going from the bench, so we’re not sure if this is an active nest or an old one. The Wool carder bees had only started to fly when we found this nest, so we will have another look in July to see if there is any action.
Above (left) is a Wool carder bee on the Lamb’s ear flowers, and on the right is a wonderful close up photo of a Wool carder bee where it’s yellow stich-like markings are clearly visible.
You can try to help Wool carder bees, by drilling 12mm diameter holes into a wooden log and placing them near to the Lamb’s ear plant.
Urban Bees was invited by patent law firm, Reddie & Grose, to run bee-related events for employees in its London, Cambridge and Munich offices during 2023.
Events included:
introducing staff to our 270 bee species in the UK, why they are so important, threats facing them and how to help them. (Slide show and talk – the Munich office zoomed in)
showing staff simple steps they can take to help bees by planting flowers for bees at home even if they only have a window box – the key is to have something flowering sequentially from early spring to late autumn (slide show and talk – in London and Cambridge and Munich zoomed in)
assembling a flat-pack bee hotel to create a nesting site for Red mason bees to check into and learning more about the bees that will use it, their life cycle, and where to locate your hotel and how to attract the bees (workshops in London and Cambridge).
Urban bees also:
highlighted a bee of the month for the Reddie & Grose social media feeds
did a Reddie & Grose podcast about bees, their importance for ecosystems, business and us.
introduced employees to a citizen science volunteering project to help bees – the Bumblebee Conservation Trust BeeWalk monitoring scheme
Aims of the partnership were to:
educate Reddie & Grose employees about the amazing bees on our doorstep, why they are so important to healthy ecosystems, mitigating climate change, business and us, and simple steps we can take to help them.
try to involve other tenants in the Whitechapel office in London to learn about bees, and to give their staff a chance to help bees at home.
try to make the Whitechapel office more bee-friendly by improving the planting and installing bee hotels through involving the sustainability manager and the facilities manager at Derwent London.
Urban Bees was asked by King’s College London to come up with recommendations for improving biodiversity across its campuses. After visiting each campus, we suggested places where bee hotels and bee observation boxes could be installed for cavity-nesting wild solitary bees.
In early May 2024, we installed some 20 bee hotels across campus gardens, the grounds of residential apartments and at the back of a sports ground. And six bee observation boxes for education purposes.
What is a bee hotel?
It’s a wooden nesting box for cavity-nesting solitary bees designed to keep the rain out, which is packed with about 20 x 15cm long bamboo tubes 6mm – 8mm diameter wide. It is positioned at least a metre off the ground in a warm spot.
What is bee observation box?
It is a larger wooden nesting box designed to enable you to see the nesting habits of some wild, solitary bees through a Perspex cover. Its removable ‘window’ panels allows you to observe the action without moving the inner two-sided, slide-out wood cartridge which has channels to create ‘tunnels’.
Which bees could I see?
The most likely inhabitants are Red Mason Bee, (Osmia bicornis) which build their nests from late April to the end of June. Later in summer, Willughby’s Leafcutter Bee, (Megachile willughbiella), or the Patchwork Leafcutter Bee, (Megachile centuncularis) may nest. These bees are excellent pollinators and docile. They don’t sting. They nest alone, but often next door to each other, so one bee may check in to three tubes and lay 10 eggs in each, and other few bee do the same.
What might I observe?
Mason bees build mud walls along their particular ‘tunnel’, creating cells in which larvae develop.
Mated females will load up the hairs on their abdomen with as much pollen as they can – often seeming bright yellow in the process. They crawl to the end of their chosen tunnel and create a neat ball of pollen, on which they will lay their egg (see photo above). Then they will fly backwards and forwards holding mud balls and ‘brick up’ that cell.
They will continue this exhausting work, filling each cell and building a mud wall between each until the tunnel is full of perhaps nine or ten cells (see photo above) The eggs containing males are laid right at the front of the tunnel and females at the back.
Then they will plug the front of the tunnel with mud, so you can see that it is being used.
Life cycle Over the next few months the larvae will hatch and slowly eat the pollen: by September each will form a brown cocoon. This is how they will overwinter.
In March or April, depending on temperatures, males will hatch first. It’s amazing to watch the bees bite their way out through the hard mud walls, the outermost bees first (see photo above).
The males go to collect nectar from nearby flowers to build up their energy for mating and hang around the box waiting for the females to emerge.
Leafcutter bees have a similar approach, but use pieces of leaf instead of mud. Females will find tough leaves – roses are favourites – and bite away a neat circle of the leaf.
They then fly backwards and forwards carrying the leaf discs in their front legs (see photo above) and stuff each one – with some effort – down the tunnel. Using their saliva, they overlap and stick the discs together, making a cylinder about the size and shape of a cigarette butt.
Into this they create a pollen ball, lay an egg on it, then seal the ‘butt’ with another few layers of leaf discs. This process repeats until the tunnel is full of egg-filled cylinders, then the front is plugged with layers of chewed leaves.
The following year, new bees will chew their way out of their containers and the cycle will start again.
We have designed our own Urban Bees flat-pack Bee Hotels.
Our bee observation boxes are supplied by Bee Equipment. More information here.
Mining bees
Of the 250 wild solitary bee species in the UK, many nest in tunnels in the ground and are mining bees. While we were doing the install at Great Dover Street Apartments we noticed a small hole in the soil below our feet and a bee flying low around it. On closer inspection we discovered that it was a Grey-patched mining bee (Andrena nitida) making her nest in the lose, bare soil. It reminded us that it’s important to have bare patches of soil where mining bees can burrow into the ground and lay their eggs.
We didn’t get any good photos, but here is one of the Grey-patched mining bee by Penny Metal.
Feeding the bees
Wild bees need nesting sites and nectar and pollen-rich flowers.
Now we are going to be working with the gardeners across all the campuses and residential settings to greatly improve the forage for solitary bees throughout the year. Without the nectar and pollen-rich flowers in early spring to late summer, the solitary bees won’t forage and they won’t use the nesting sites.
We are also embarking on a series of educational event to introduce students and staff to the bees and how to help them. The first one is a walkabout on Guy’s campus on 28 May. Details are here
Eight months after we planted lots of new flowers (in response to the drought in 2022) on the roof 8 storeys up on Bread Street in the City, many are thriving, and have been joined by some blow ins – flowers that have arrived another way. Birds have deposited the seeds, or they’ve been blown in -like the yellow, dandelion-like flower above and the patch of Red dead-nettle below (middle), which is important food for long-tongued bees in spring, like Hairy-footed flower bees and Common carder bees. The red campion is back, despite removing most of it as it was taking over, and I want to have a diversity of flowering plants throughout the year to feed bees, not a dominant few.
I realise that I can’t just let the roof do it’s own thing, or else the sunnier planter would have been covered with nothing but Red hot poker (kniphofia). It absolutely loves it up there – in the heat, the wind, the cold, the rain. It is the hardiest plant I’ve ever come across.
It will be interesting to see if we see more bees visiting this summer than last year when there was much less diversity of flowering plants. In summer 2023, the survey of pollinators on the roof by Pollinating London Together found a furrow bee on Willowherb (Epilobium) – another blow in – as well as less interesting honeybees and Buff-tailed bumblebees.
PL’s Greenspace Habitat Survey 2023 scored the roof 14/20. It scored 80% on diversity of flowers for pollinators. I’m hoping for 100% this year. But only scored 3/8 for number of pollinator species found on the days of the survey. I would argue that one day was too hot for most pollinators, and another was too windy. But they are the extremes that pollinators face on a rooftop in the City of London during the summer.
The first 2024 PLT survey is scheduled for 23 May, so let’s see how the roof fares compares to last year. I think it will be much more attractive to bees if the conditions are good.
Year-long partnership with Reddie & Grose Patent law firm with offices in east London, Cambridge and Munich. Involved introducing staff to our 270 bee species, talks on how they can plant for bees at home and making bee hotels for Red mason bees to check into. We also highlighted a bee of the month for their social media feeds.
Created a new bee garden on the 12th floor of Bartholomew Close in the City (pictured middle). We installed 4 wooden planters each around 2m x 2m and 30mm deep, fitted with a drip irrigation system, and filled one with spring flowering plants, another with mid summer plants, a third with later summer plants and the final one we sprinkled with seed bombs to create a wildflower meadow. It has thrived once we ensured the outdoor tap wasn’t switched off every Monday morning!
Gave a bee talk to architects at Farringdon Design Week on the subject of ‘How architects and designer can save urban bees and pollinators’. It was hosted by KN International, a cool office furniture design company. And they gave me the t-shirt!
4.Regent’s Parkbee safaris in May, June, and August (July walk cancelled due to high winds). Advertised by Regent’s Park as a free activity, huge numbers of people signed up but usually less than 20 turned up on the day, expect for August when we had more than a full house (all pictured in the allotment, left). I was assisted by May Webber, community engagement officer, and than Nick Tew, biodiversity research officer, who helped with nets and glass tubes.
5 Three-year contract with PWC to improve biodiversity at UK offices and engage staff in sustainability via bee-related activities, like bee safaris on the terraces at their Embankment office(middle photo) where I’d worked with gardener, Mat Bell, to make them more bee-friendly throughout the year .
6 Found tiny Furrow bees and Yellow-face bees on 3 of my City rooftop bee gardensduring surveysfor Pollinating London Together, a charity set up to improve biodiversity in the Square Mile. I offered my roofs at Bread Street (9 floors) and Bartholomew Close (12 floors) and at Weil law firm (8 floors) for pollinator surveys this summer. Thanks to pollinator ecologist, Konstantinos Tsiolis (pictured right on Bread Street with a tiny Green furrow bee), who was equipped with nets, glass tubes, and eye glasses, he recorded tiny bees that I couldn’t see with the naked eye. It was so exciting to record them so high up. And it just shows that when you plant a diversity of bee-friendly flowers, you get a diversity of wild bees, even in the City. More information here. The results will feed into a PLT report out early next year.
7 Produced 3 x bee information boards for the Post Building in central London to inform the public about the wild bees they may see when they visit the roof: Red mason bees (using the bee hotels installed above in the info boards), Leafcutter bees (who may also check into the bee hotels) and Hairy-footed flowers that will visit the wallflowers in early spring. We worked with Q&S Commercial Landscaping company on this project (and others throughout the year). Thanks to Ola Wiebe for design and Penny Metal for photos.
8 Installed a small bee garden at the Hilton London Metropole – in 5 hexagonal wooden planters and 2 x rectangular planters for climbers. We planted it up on a terrace in late autumn, so it will be interesting to see how the spring bulbs and wallflowers look come March/April, and which wild bees they are feeding. My guess is Hairy-footed flower bees.
9 Bee hotel workshops – Brian designed our very own wooden flat-pack bee hotel. He worked with a local ‘cutter outer’ to get the 5 piece flatpack . It can be easily assembled under instruction with wood glue by people like me who can’t put Ikea furniture together. The idea was to use the bee hotels in corporate workshops. Previously we’d been using plastic water bottles, which we didn’t feel comfortable doing. The hotels have proved a great success with children and adults alike at Weil, Reddie & Grose and KPMG. Looking forward to doing many more in 2024. We’ve also sold a few online.
10. Amazon bee garden finally fed bees (5 floors up, near the Barbican)- after an irrigation system was added in spring, and though it’s tiny, it feeds Common carder bees on knapweed, and Red mason bees are nesting in the bee hotels attached to that pole pictured at the back of the tallest wooden planter. It just shows what difference a regular water source makes to the health of the plants and the variety that can be grown. Even the lavender, rosemary and sedum all did better.
11. Lush rooftop garden (5 floor roof terrace in Soho) went from strength to strength. Such a pleasure to see it attracting Wool carder bees, pictured in the middle, on the clump of Stachy byzantina (Lamb’s Ear) I’d planted for them, and Small scissor bees (pictured above right) on the Campanula, as well as Common carder bee, Buff-tailed bumblebees, Furrow bees and nests and food for Red mason bees. In June I gave my annual talk for staff on the rooftop- and the bees arrived right on cue!
12. Bees to See in 2024 calendar is even more beautiful than this year’s. Stunning close up photos taken and selected by Penny Metal. Moreover, we’ve taken on board people’s feedback and have improved the calendar so it now includes:
measurements to aid identification
photos of some of the most common hoverflies and wasps that mimic bees to help people tell them apart
