Nesting habitat: the half of bee gardening that is not flowers

Where bees actually live

The image of a bee nest is a hive or a bumblebee's tussock, and both are unrepresentative. The great majority of the world's bee species are solitary: one female excavates or occupies a nest, provisions a few cells with pollen and nectar, lays an egg on each, seals them and dies. No colony, no comb, no honey, and no help from anyone.

Bare ground is the scarce resource

Ground-nesting bees need soil they can dig: bare or sparsely vegetated, well drained, and warm. South-facing banks, path edges, thin lawn, and the base of walls all qualify. What they cannot use is soil under bark mulch, under weed membrane, under dense planting or under decking — and modern garden practice covers all of it.

• Leave a sunny patch unmulched and undisturbed. A square metre is worth having; several are better.
• Do not level or turf a south-facing bank if you have one. Sloped bare soil is prime habitat.
• Tolerate thin patchy lawn. Mining bees nest in it and the small volcano-shaped spoil heaps in spring are the sign it is working.
• Avoid disturbing the same ground repeatedly. Nests are in use for weeks and the adults are underground far longer.

Stems, wood and bee hotels

Cavity nesters use hollow or pithy stems and old beetle burrows in dead wood. Bramble, teasel, hogweed, angelica and elder all provide them, and the requirement is simply that the stems are left standing rather than cut and cleared in autumn. Cutting some stems at an angle in late winter, leaving the cut ends exposed, produces exactly what a small carpenter bee wants.

• Tubes 4 to 10 mm across, smooth inside, closed at the back, 15 cm deep or so.
• Full morning sun, sheltered from rain, firmly fixed so it does not swing.
• Replace or clean the tubes every year or two; paper liners make this practical.
• Several small hotels spread around a garden beat one large one.

Distance is a constraint people forget

A honey bee colony forages over several kilometres. A small solitary bee may work within a couple of hundred metres of its nest, and every trip has to return. Forage and nest site therefore have to be near each other: a garden with abundant flowers and no nesting habitat supports visitors from elsewhere rather than a resident population, and one with nesting habitat and no forage supports nothing.