Building a Bug Hotel for Heathland Insects and Solitary Bees

Why heathland insects need a helping hand

Lowland heathland is one of Britain's rarest habitats. Once stretching across vast swathes of southern England, the Midlands and parts of Scotland, it has shrunk dramatically over two centuries, and what remains is often fragmented by roads, housing and intensive farmland. For the insects that depend on heather, gorse, bell heather and tormentil, those gaps can be impossible to cross.

This is where our gardens come in. If you live near heathland — in Surrey, Hampshire, Dorset, Norfolk, or the Welsh and Scottish uplands — your plot can act as a stepping stone. A well-placed bug hotel, paired with the right plants and a patch of bare ground, gives solitary bees, mining bees, wasps and beetles somewhere to nest and shelter.

Knowing your guests: what each insect actually needs

Before you reach for the drill, it helps to understand that "bug hotel" is a catch-all term. Different insects want very different things, and a good hotel offers several options under one roof.

• Mining bees, such as the heather mining bee, excavate tunnels in bare, sandy soil. They will ignore hollow tubes entirely.
• Mason bees and leafcutter bees nest in hollow stems and old beetle borings, capping their nests with mud or chewed leaves.
• Solitary wasps often use pithy stems, bramble or dead wood with existing holes.
• Beetles, lacewings and over-wintering invertebrates shelter in dead wood, loose bark, leaf litter and stacked stones.

A hotel offering only bamboo canes is therefore only half a hotel. The best designs mix materials and include a ground-level sandy area.

Choosing a site and gathering materials

Position matters more than size. Pick a spot facing south or south-east, sunny for most of the day and sheltered from prevailing wind. Mounting your hotel on a fence post, wall or shed keeps nesting tubes dry and out of reach of ground predators; a height of one to one and a half metres is about right.

Gather materials from your own garden, or from woodland where you have permission to collect:

• Hollow stems: bamboo, elder, teasel, bramble, raspberry canes, spent sunflower or fennel stalks.
• Dead wood: an untreated log or block of oak, ash or beech, ideally with existing beetle holes.
• Pithy stems: reeds, hogweed, cut buddleia or hydrangea.
• Sand and loam: sharp sand, subsoil and a little clay — never compost or bark mulch.
• Bricks with holes, broken roof tiles and dry leaf litter.

Avoid treated timber, plastic mesh and anything painted or varnished. Insects are sensitive to chemicals, and a weathered, untreated frame will last for years anyway.

Building the hotel, layer by layer

Build a simple open-fronted box from untreated timber, roughly 30 centimetres deep. Depth matters: shallow hotels dry out too quickly and leave larvae vulnerable. Fix a sloping roof to shed rain and leave the front open.

Now fill it in sections. There is no single correct arrangement, but this works well:

• Top layer: a block of dead wood drilled with holes from 3 to 10 millimetres in diameter, each about 10 centimetres deep. Drill horizontally and sand the entrances lightly to remove splinters.
• Middle layer: bundles of hollow stems, cut so one end is open and the other closed by a natural node. Pack them tightly — loose canes wobble and discourage nesting.
• Lower layer: pithy stems, a few bricks with holes, and a small bundle of dry leaves or straw for beetles.

Angle the whole structure very slightly forward, so rain runs off rather than into the tubes, and face the open side towards the morning sun.

The sandy pocket: essential for mining bees

This is the part most gardeners miss, and it is arguably the most valuable. Mining bees cannot use a wooden hotel. They need bare ground.

Choose a sunny, south-facing spot at the base of your hotel or nearby. Clear a patch of turf about 60 centimetres across and fork the soil to a depth of 15 to 20 centimetres. Mix in sharp sand and a little subsoil so the ground is free-draining; roughly equal parts sand and loam is ideal. Do not add compost, manure or mulch — mining bees want lean, bare, warm earth.

Keep the patch free of weeds and long grass by gently hand-weeding through spring and summer. You will know it is working when you spot small, neat holes with little spoil mounds around them, and bees hovering low over the sand before disappearing underground.

Looking after your hotel through the year

A bug hotel is not a build-it-and-forget-it project. Left alone, tubes clog with old nests, mould and parasites, and the structure slowly declines.

• Late winter: replace any damp, mouldy or blocked stems with fresh ones. Work gently, as some larvae may still be inside.
• Spring: keep the sandy patch clear and resist tidying nearby seed heads, which over-wintering insects use.
• Summer: leave the hotel undisturbed while bees are nesting, and avoid spraying nearby plants.
• Autumn: add a little fresh dead wood or leaf litter. Do not move or rotate the hotel — insects orientate to its position.

You will not attract every heathland species to a garden, and that is fine. What you will do is provide a reliable, chemical-free refuge for the pollinators that stitch our remaining heathland together. That is a genuine contribution, and it starts with a few hollow stems and a patch of bare sand.