Eleanor Hartley
Why solitary bees need a helping hand
Solitary bees are the quiet workhorses of the British countryside. Unlike honeybees, which live in colonies, or bumblebees, which form small annual nests, most of our 250-odd solitary bee species nest alone. Each female finds a suitable tunnel, lays her eggs, stocks it with pollen and nectar, then seals it up and moves on. Many of these bees favour hollow plant stems, old beetle holes in dead wood, or cracks in walls. As gardens become tidier and old trees are cleared, those natural nesting places are harder to find. A bee hotel made from garden materials is one of the simplest, cheapest ways to give them a hand.
You do not need fancy kit. A block of untreated wood and a bundle of hollow stems will do the job beautifully. The secret is in the details: the right hole sizes, the right depth, and a sunny, sheltered spot where the bees feel safe.
Choosing the right spot for your bee hotel
Solitary bees are cold-blooded. They need warmth to become active, so position your hotel where it catches the morning sun. A south or south-east facing wall, fence, or shed is ideal. Avoid spots that are shaded all day or exposed to driving rain. A little shelter from prevailing wind helps, too.
Mount the hotel at least a metre off the ground, and make sure it is firmly fixed. A wobbling hotel puts bees off, and a stable one is easier to check without disturbing the occupants. Keep it away from bird feeders and dense shrubs where predators might lurk. If you have space, make two or three small hotels rather than one large one. Solitary bees are not territorial, but a choice of sites gives them options.
Drilling holes in untreated wood
A wooden block nest is the classic bee hotel. Use untreated hardwood or softwood — oak, ash, beech, or even a thick offcut of scaffolding board. Avoid pressure-treated timber, which can contain chemicals harmful to larvae. Cut a block roughly 15–20cm square and 15cm deep. The depth matters: tunnels shorter than 10cm tend to produce more male bees, while longer tunnels allow females to develop.
Drill holes between 2mm and 10mm in diameter, using sharp bits. A mix of sizes attracts different species — small holes for tiny species, larger ones for leafcutter and mason bees. Drill to a depth of 10–15cm, but do not go all the way through. Leave at least 2cm of solid wood at the back. Space the holes about 1–2cm apart so the wood does not split. Sand the entrance holes lightly to remove splinters, then tap out all the sawdust. Mount the block with the holes facing slightly downwards, or at least horizontal, so rain cannot run in.
Bundling hollow stems for a simple nest
Hollow stems are just as effective and cost nothing if you have a few canes or reeds lying about. Bamboo, reed, teasel, and the dried stems of many garden perennials work well. Cut them into lengths of 15–20cm, using a sharp pair of secateurs. The stems should be open at one end and closed at the other — a natural node at the back is perfect. If both ends are open, push a dab of clay or a plug of wood into one end.
Gather a tight bundle and slide it into a short length of drainpipe, a clean tin can with the sharp edges folded over, or a wooden frame. Pack the stems snugly so they do not rattle, but do not crush them. Tie the bundle with garden twine if needed. Hang it in the same sunny, sheltered spot as your wooden block. Different diameters will attract different bees, so mix them up.
Maintaining your bee hotel through the year
Once your hotel is up, resist the urge to fiddle. Solitary bees overwinter as larvae or pupae inside the tunnels, and moving or cleaning at the wrong time can kill them. Leave the hotel alone from autumn through to late spring. In early summer, you can gently brush out any empty holes with a dry bottle brush, but do not dig into sealed tunnels.
After a few years, the wood may become splintered and the stems brittle. Replace the wooden block or the stem bundle every three to four years. If you notice mites, small parasitic wasps, or mould, simply remove and replace the affected part. Never use insecticides near the hotel. Provide a patch of damp mud nearby for mason bees, and leave some fresh leaves for leafcutter bees.
What to expect from your new guests
Patience is part of the pleasure. The first bees usually appear in early spring, with males emerging first and waiting near the hotel for females. You may see them sunning themselves on the entrance holes or patrolling the area. Red mason bees often cap their tunnels with mud, while leafcutter bees use neat circles of leaf. Each tunnel contains several eggs, each with its own pollen parcel.
By late summer, the hotel will be sealed and quiet. The next generation is inside, growing slowly. Come spring, the cycle begins again. A bee hotel will not replace lost wild habitat, but it is a small, practical act of countryside kindness. One sunny wall, a few drilled holes, and a bundle of stems — that is all it takes to welcome these gentle, hardworking neighbours.
