Leafcutter bees require a tubular shaped site in which to construct their cells from leaves. In nature, they will use the abandoned holes in wood left by wood-boring beetles, holes in the ground vacated by earthworms, dried out hollow stems such as sweet cicely, and a variety of suitable cavities. Nests have been found down the sides of flowerpots, in the legs of patio furniture, and in garden umbrellas.
You can provide suitable habitation for the leafcutter to build her nest either by purchasing ready-made nests (these come either as cardboard tubes, drilled wooden blocks, boxes packed with bamboo, or other shapes and designs), or by making your own nest.
Where to buy the nests:
The Oxford Bee Company solitary bee nests (below left) can be purchased from various places online, for example WigglyWigglers & CJ Wildbird Foods. Or search online for ‘Oxford Bee Company’ for other suppliers. Other solitary bee houses can be bought from: Co-Op Plan Bee & Habitat Aid
Above left: Oxford Bee Company nesting tubes, centre: purchased bamboo bee house, right: home made bee house of drilled wood.
Below: A purchased wooden bee house: left: freshly-sealed nests, centre: the following Spring, one tube has hatched, right: abandoned attempt to nest in one of the larger holes.
I feel I must say that although this bee house above looks beautiful, as you can see the bees have not favoured it, and prefer the cylinder-type houses. The reason for this seems to be that many of the holes are simply the wrong size or shape for a leafcutter. They prefer to use tubes which are just larger than themselves, which is usually about 8-10mm. One bee last year attempted to nest in one of the lower holes, and gave up the attempt (see above, right). The two circular holes either side of the ones which have been nested in cannot be used at all, because there are small nails blocking the tubes. So if you are purchasing bee homes, please look out for all these things before making a selection.
Make leafcutter bee nests yourself.
You can also make nest sites yourself out of old garden canes and similar stems, or by drilling holes in a block of wood, and these are successful. But I have found that the bees can be a little fussy about the diameter of hole they prefer, and many of the tubes may go unused if they are too big or too small – however these may be used by other bees or insects. I have had mason bees (which make their cells out of mud) nesting alongside the leaf-cutters in my nests.
This year I’ve decided to try drilling holes into wood to see if my bees will take to these. The wood needs to be untreated. The holes need to be as long as you can make them – preferably towards 20cm, and between 8-10mm in diameter. This is particularly rough wood, and I’m not sure the bees will like it, as I have read that they do not like jagged pieces around the mouth of the nest. I have made the wood as smooth as possible (not terribly easy with this grain!) using sandpaper. The nest is sited on a new brick ‘wall’ built straight onto the ground, so hopefully there will be no more off-putting vibration. The wooden structure is part of an old stool, and I’ve roofed the whole under slate and an old roof from one of the hedgehog houses.
As you can see I still have more blocks of wood to drill, and I will pack the rest of the space with sweet cicely and bamboo, to offer the bees as many options as possible. Fingers crossed! I’ll update this section later with more information on building the bee nests. In the meantime, follow this link for more details on how to build a solitary bee house.
Siting your nests:
Bees, being cold-blooded, require the sun’s warmth first thing in the morning to enable them to fly out and gather food. It is therefore essential that the nests are sited somewhere dry where they will catch the morning sun.
The first year I tried the cylinders I attached them to a sunny wooden fence, but while there was some interest from bees that summer, none of them nested. I have since found that the bees do not particularly like the tubes when they are new, and prefer them to be somewhat weathered. However, I have also heard that the vibrations caused by the fence moving in the wind may also have discouraged them from settling. So I have followed advice to place the cylinders in a stable and sunny spot, a few feet from the ground, and preferably somewhere the tubes won’t get wet. I had quite a bit of success with the nests outside my old summerhouse door. However, the summerhouse had to come down when my new studio was built, and so I needed to find somewhere new that the bees would favour.
I don’t have many South-east facing areas in my garden, so I was rather limited in choice. As you can see in the pictures below, for two years running I sited the nests right outside my studio door, so I could observe their activities. This is perfectly safe as leafcutter bees, unlike honey bees, are very unlikely to attack or sting. However, I don’t think the bees enjoyed the vibrations caused by people walking on the decking, and after some initial interest last Spring the nests were completely unused that year. Therefore this year I’ve sited the bee houses on a small brick wall to the side of the decking, and hope that they will come back again.
Over wintering your nests:
Once the summer is over and the tubes are all sealed, you will need to put the cylinders somewhere dry and cool for the bees to over-winter. A cool garden shed seems ideal, but don’t forget to take them out again next Spring! Once Spring comes, re-position your cylinders where they were the previous year, and wait for the new bees to hatch. My leaf-cutters begin to hatch in the first weeks of June, towards Midsummer.
Lastly: Don’t be discouraged if no bees nest in the first year. It may well take a little while for them to find the nests and settle in. I had no bees in my nests for the first year. Also, you will find that if you stop spraying chemicals in your garden, and plant more of the bee-friendly plants, you will see a definite increase in bees including leafcutters, as well as other interesting wildlife in your garden.
Things you will see once the bees start using your houses:
The leafcutters will become active at the end of May or beginning of June. The first ones in my garden generally begin to hatch at the end of the first week of June, depending on the weather. If you have nests which have not previously been used, you will hopefully be lucky enough to see bees checking out potential homes about this time. The image below left shows a bee exploring new nest tubes. Later in the year you will see her building up cells from leaves found in the surrounding area (centre images), and then hopefully next Spring you will see new bees emerging, as in the image below right. The nests are bright green when they first seal them, and then fade to a reddish brown over time. This does not mean that the nest is abandoned, just that the bees inside are developing. See above for information on how to overwinter your bees.