Why a Simple Shelter Is Worth Building

British gardens have quietly become some of the most important wildlife habitat in the country. Hedgerows have gone, wildflower meadows have shrunk, and yet our back gardens, allotments and window boxes now form a patchwork of corridors that solitary bees, ladybirds, lacewings and hoverflies rely on. Putting up an insect hotel is one of the easiest ways to give them a hand — and it needn't cost a penny. A few hollow stems, a handful of pine cones and an offcut of untreated timber will do the job beautifully.

It helps to know what you're building for. An insect hotel isn't a hotel in the holiday sense; it's a set of small, dry cavities that mimic the nooks insects would naturally find in dead wood, old walls and hollow plant stems. Get the details right and you'll have tenants by spring.

Finding a Home for Your Hotel

Position matters more than most people realise. Choose a spot facing south or south-east, so morning sun warms the structure and helps residents get going on cool days. Shelter it from prevailing wind and driving rain — under the eaves of a house, against a sunny shed wall or on a fence post all work well. Mount it at least a metre off the ground and fix it firmly; a hotel that sways in the breeze won't be used.

For the frame, look at what you already have: an old wooden pallet, a broken drawer, a wine crate, a stack of bricks with gaps between them, or a length of guttering cut into sections. Untreated timber is best. Avoid anything varnished, painted or pressure-treated with preservatives, as these can harm the insects you're trying to help.

Filling the Rooms: Hollow Stems and Drilled Wood

These two materials are the heart of any good hotel, because they're what solitary bees actually nest in.

Hollow stems: Bamboo, reed, elder, teasel and fennel all give you ready-made tubes. Cut them into lengths of 15–20cm, making sure one end is closed — a natural node or a sawn end that stays capped. Bundle them tightly into a compartment, open ends facing out, and pack the gaps with dry material so nothing rattles. A loose bundle lets in light and predators, so firm is better.

Drilled wood: Take a block of untreated hardwood — oak, beech, ash or apple — at least 10cm deep. Drill holes from 2mm to 10mm across, in a range of sizes, spaced about 1.5cm apart, stopping short of going right through. Sand the entrances lightly to remove splinters, which can tear delicate wings. Softwood is a poor choice: it splinters, and the tunnels soon crumble.

• 2–4mm holes suit small solitary bees and some wasps
• 5–7mm holes are the sweet spot for red mason bees
• 8–10mm holes attract leafcutter bees

Pine Cones, Bark and Cosy Corners for Ladybirds

Not every guest wants a tunnel. Ladybirds, lacewings and a host of beetles look for dry, tucked-away crevices to overwinter in, and pine cones are perfect for the job. Fill a compartment with loose cones, then add strips of dry bark, crumpled corrugated cardboard and a scattering of dry leaves.

Lacewings like rolled-up corrugated cardboard, open-ended, because the flutes give them somewhere to shelter. Straw, wood shavings and dry leaf litter work well in the lower sections, where damp is more likely to creep in.

Keep wet-loving materials at the bottom and bee tubes near the top, under a small overhanging roof. A piece of slate, a strip of roofing felt or an old tile will keep the rain off and add years to the structure's life.

What to Leave Out

A few well-meant additions do more harm than good.

• Plastic drinking straws — they trap moisture and don't breathe, so larvae can rot.
• Glass jars and open bottles — these become death traps, holding heat and letting insects in but not out.
• Honey or sugar syrup — never needed, and it attracts wasps and disease.
• Painted or treated wood — chemicals leach out over time.
• Sharp metal edges — old tin cans look charming but can slice wings.

Remember too that a hotel is a supplement, not a substitute. Leave a patch of bare, sunny ground for mining bees, keep a few dead stems standing over winter, and plant nectar-rich flowers nearby — lavender, borage, foxgloves, oregano and thyme all earn their keep.

Looking After It Through the Year

Once your hotel is up, the best thing you can do is mostly leave it alone. Resist the urge to tidy it in autumn; the whole point is that it stays dry and undisturbed through the coldest months. Fix it firmly so winter gales don't shake it apart.

Come spring, check for activity — a small plug of mud or neatly cut leaf circles at the entrance of a tube means you've got tenants. In late summer, once the bees have emerged, gently clear out any tubes that have gone damp or mouldy and replace them with fresh ones. A full clean-out every two years or so keeps the structure healthy.

And if your first attempt isn't a roaring success, don't worry. Insects are fussy about microclimate, and it can take a season or two for word to get around. Build it well, put it in the right spot, and let the garden do the rest.