Why solitary bees deserve a place in your garden

Britain has around 270 species of wild bee, and the vast majority of them are solitary. There is no hive, no queen and no honey store — just a single female who finds a tunnel, fills it with pollen and nectar, lays an egg, seals it up and moves on. Red mason bees, leafcutter bees and the small yellow-faced bees all live this way, and together they pollinate a huge proportion of our garden fruit, vegetables and wildflowers.

What they struggle to find is somewhere to nest. Old beetle holes in dead wood, hollow plant stems and crumbling mortar have all become scarce in tidy gardens and cleared hedgerows. A bee hotel is a small, useful way of putting some of that back — and because solitary bees are gentle and rarely sting, it is a safe project to hang near a path, a shed wall or a kitchen window.

What you need, and what to avoid

The principle is simple: dry, breathable tunnels, closed at one end. Anything else invites damp, mould and disappointed bees. Before you start, gather a few things.

• Untreated hardwood — oak, ash, beech or sycamore offcuts. Avoid softwood such as pine, which splinters and frays, and steer clear of anything painted, varnished or dipped in wood preservative.
• Hollow stems — bamboo, teasel, hogweed, fennel, buddleia, sunflower, raspberry canes and bramble. Hogweed sap can blister skin, so wear gloves when cutting it.
• A container — a clean tin can with the label removed, an offcut of drainpipe, a terracotta pot or a small untreated wooden box.
• Tools — a drill with bits from 2mm to 10mm, a saw, sharp secateurs, sandpaper and galvanised wire or brackets for mounting.

Skip plastic drinking straws and clear plastic or glass tubes. They trap condensation, grow mould and can suffocate the developing bees inside.

Project one: the drilled wooden block

Choose a block at least 10cm deep and ideally 15cm. A sawn, flat-faced piece is better than a round log, because drilling into end grain tends to split the timber as it dries.

Drill a range of hole diameters between 2mm and 10mm. Different bees need different sizes: small species use 2–4mm, leafcutters favour 6–7mm, and red mason bees are happiest at around 8mm. Drill each hole so it stops 1–2cm short of breaking through the back — the bees need a sealed wall behind them. Space the holes roughly 15mm apart so the block does not crack, and keep them level or angled very slightly downwards so rainwater cannot run in. Finally, sand the entrance of every hole to remove rough edges, which can tear a bee's delicate wings.

Project two: the bundle of hollow stems

Cut your stems into lengths of 15–20cm, always cutting just below a node so one end stays sealed by the natural wall of the plant. Pack them tightly into your container with the closed ends at the back — loose bundles let in light and give parasitic wasps and other predators easy access.

Once full, trim the front ends with secateurs so the openings sit flush and neat. Bees find a tidy, even face much easier to read than a ragged jumble of stems pointing in all directions. Stand the bundle somewhere dry for a few days before mounting it, just to make sure nothing inside is holding moisture.

Siting and mounting your hotel

Position matters more than size. Fix your hotel to a south or south-east facing wall, fence or shed, ideally under the shelter of an eave or overhang so driving rain cannot soak it. Mount it between 1m and 2m above the ground, tilted very slightly forward to shed water, and keep it steady — a wobbling box puts nesting bees off.

Place it near flowers for foraging, and within a few metres of bare earth or a muddy patch. Leafcutter bees need mud to seal their cells, and mason bees use it to cap the tunnel entrance. Avoid hanging it directly beside a bird feeder, as blue tits and great tits will happily pick off emerging bees. Once bees have moved in, leave the hotel where it is — moving it mid-season can kill the brood inside.

Looking after it through the year

Leave the hotel completely alone over winter. The bees are inside as larvae, tucked up in silk cocoons, and they need the cold to develop properly. Adults emerge in spring, usually males first, and spend a few weeks mating and nesting before the cycle begins again.

Each autumn, once the bees have finished and gone, gently replace the hollow stems, as they become brittle and can harbour mites and pollen mould after two or three years. Wooden blocks can simply be re-drilled or swapped for a fresh one. Never prise open an occupied tube to see what is happening inside.

And do not worry if your first year passes quietly. Solitary bees are slow to find new sites, but once a hotel has been used, the bees that hatch from it often return to the same spot. Plant a few native flowers nearby — foxglove, wild marjoram, red clover, viper's bugloss or bird's-foot trefoil — and you have given them both a home and a larder.