Why a bug hotel earns its place

The UK has around 270 species of solitary bee, and almost none of them live in hives. Red mason bees, leafcutter bees and their relatives nest in hollow plant stems, old beetle holes and cracks in dead wood. Add beetles, ladybirds, lacewings, earwigs and woodlice to the guest list and you have a small, hard-working community that will pollinate your fruit trees and eat a fair number of aphids besides.

The trouble is that tidy gardens are short of the messy things insects need. We cut back stems, stack logs on the bonfire and rake up every leaf. A bug hotel is simply a way of keeping some of that material in a useful arrangement rather than losing it. It will not replace a hedge or a wild corner, but it gives a great many creatures somewhere dry to shelter, and it costs you nothing but an hour and a bit of garden waste.

Choosing a spot that works

Placement matters more than the frame itself. Solitary bees need warmth to fly, so a south or south-east facing spot is ideal, ideally against a wall or fence that holds a little heat. Shelter it from the prevailing south-westerly wind, and give it dappled rather than baking sun. Raise the whole thing 20–30cm off the ground on bricks or a couple of paving slabs, so it does not sit in damp soil.

Keep it at least a metre or two from bird feeders, bird boxes and anywhere cats like to sit. A mesh screen with 15–20mm holes over the front of the bee section will let bees in and keep tits out, which is worth doing if your garden is busy with birds.

Building the frame in an afternoon

An old wooden pallet with the slats cut down makes a fine back panel, and a sturdy crate, an orange box or a few untreated timber offcuts will do just as well. Aim for something roughly 60cm wide, 60cm tall and 20–30cm deep, divided into a few compartments so you can fill each with a different material.

• Fix a roof with a generous overhang — a piece of corrugated sheet, a slate, a spare tile or some felt on battens, tilted slightly forward so rain runs off.
• Leave the front open but consider a small lip at the base to stop material tumbling out.
• Use untreated, unpainted timber. Tanalised or pressure-treated wood can leach chemicals, and insects are fussy about what they touch.
• Fill the lowest compartment with soil, stones and broken terracotta, then work upwards with drier, airier material.

What to stack, and what to leave out

Garden waste is the whole point, so raid the prunings pile and the log store rather than buying anything.

• Hollow stems: bamboo, buddleia, teasel, fennel, spent raspberry canes and sunflower stalks. Cut them into 15–20cm lengths, bundle 20 or so tightly with twine, and push them in with one open end facing out and the other closed. Bees need holes between 2mm and 10mm across — a mix of sizes suits a mix of species.
• Dead wood: untreated logs and thick branches, especially with loose bark still attached. Drill holes 3–10mm wide and about 10cm deep, angled very slightly downwards so rain cannot collect, and pack several logs in loosely rather than sealing them tight.
• Dry leaves: stuffed into a corner or a wire cage, they are perfect for lacewings, ladybirds and hibernating butterflies. Combine with short twiggy prunings to stop the leaves matting down.
• Stones and broken pots: stacked with gaps, these make cool, humid nooks for ground beetles, centipedes and the occasional toad.

What to leave out is just as important. Do not fill compartments with grass clippings or wet garden compost — they heat up, turn anaerobic and go mouldy. Avoid hay, which rots quickly, and skip sawdust, plastic, glass and anything painted or varnished. Large empty chambers look impressive but are of little use to insects, and they make excellent homes for rats and mice, so keep the voids small and tightly packed.

Keeping it going through the year

From October to March, leave it completely alone. Insects and amphibians will be tucked in for the winter, and disturbing a hibernating queen is usually fatal. Come spring, gently check the bee tubes. Replace any that are damp, blackened or blocked with mould, and swap in fresh hollow stems every February or March — mason bees will happily reuse a tube, but parasites and mould build up over time.

Top up the leaf compartment each autumn as it settles, and check the roof after storms. If the whole structure starts to slump, a couple of extra battens across the front will hold everything in place without sealing it up. Within a season you should see neat mud plugs in your bamboo stems, small round leaf-cut holes in the rose leaves nearby, and a steady trickle of small lives moving in. That is a very good return on a pile of prunings.