At a glance
The UK has around 270 species of bee, of which only one – the honey bee – lives in a large colony with a queen and workers. The remaining 269 species are solitary bees: each female builds her own nest, lays her own eggs and provisions them independently without any cooperative colony structure. Solitary bees are the UK’s most effective pollinators – weight for weight they pollinate more flowers than honey bees because they forage less selectively and carry pollen in a looser, more transfer-ready way. Red mason bees alone are estimated to be 120 times more effective at pollinating apple blossom than honey bees.
The key conservation problem is nesting habitat. Solitary bees that nest in hollow stems and pre-existing holes – the cavity-nesting species – have lost enormous amounts of habitat as gardens have become tidier, dead wood has been removed and hedges have been replaced with fences. A bee house directly replaces this lost habitat by providing bundles of correctly sized tubes that female bees fill with pollen, lay an egg on top, then seal. The more bee houses and natural nesting materials available, the larger the local population of cavity-nesting solitary bees – which means significantly more pollination activity in the garden. If you are already working to attract bees to your garden through planting, a bee house is the natural next step.
Why solitary bees need bee houses
Unlike bumblebees and honeybees, solitary bee species do not produce honey and do not defend a colony – they are entirely harmless to humans in normal garden conditions. The females are focused entirely on provisioning their individual nesting tubes with pollen and nectar, and will only sting if physically trapped or handled roughly. This makes them ideal garden inhabitants – effective pollinators that require no management, pose no risk, and need only a suitable nesting site to establish a productive local population.
Building a bee house
The simplest DIY bee house is a wooden box packed tightly with bamboo canes cut to 15-20cm lengths. A wooden frame of untreated timber with a sloping roof overhang – to keep rain off the tube openings – provides a durable structure. The back of the box should be solid to prevent light coming through the tubes, which discourages occupation. Internal dimensions of roughly 20cm deep, 20cm wide and 15cm tall give enough space for a mix of tube diameters packed in tightly so they cannot rotate or fall out.
More elaborate versions incorporate bundles of dried hollow plant stems such as elder, bramble and fennel, drilled blocks of untreated hardwood with holes of various diameters, and rolled corrugated cardboard. The variety of tube diameters in a single house accommodates more species – a house with only 8mm bamboo serves red mason bees excellently but offers nothing to smaller species. A well-built DIY house incorporating bamboo, drilled wood blocks and some hollow stems covers the full range of likely visitors. Avoid treated or painted wood, pine cones which are decorative but ineffective, and any materials with rough internal surfaces that damage bee wings.
Tubes must be smooth inside and closed at one end. Bamboo tubes split between nodes work perfectly – the node provides the closed end naturally. If cutting bamboo between nodes, plug one end with caulk or a tightly fitted cork. Rough internal surfaces prevent bees from reversing out and can injure them. Paper tubes are a useful alternative as they can be replaced annually without disturbing cocoons still developing inside.
Choosing the right tubes and materials
Bamboo canes are the most widely available and practical tube material. Buy untreated garden bamboo of mixed diameters, or purpose-made bee tube sets that include a range of internal diameters from 4mm to 10mm. Cut bamboo tubes to 15-20cm minimum – shorter tubes produce mostly male bees which develop at the tube entrance end, with few females. Female bees develop deeper in the tube and are the ones that will nest and produce the next generation, so tube depth matters directly for population growth. Paper tubes with a cardboard insert are a useful alternative as the paper lining can be removed for inspection and replaced each year, reducing disease build-up.
Avoid plastic tubes entirely – they retain moisture, cause condensation inside and lead to mould that kills developing larvae. Avoid tubes with rough internal surfaces from knots, splits or burrs. Any tube where the internal surface is not smooth and consistent should be discarded. A well-stocked bug hotel that includes bee tubes alongside other insect habitat – hollow stems, drilled wood, bundled twigs – creates a more varied habitat structure than a dedicated bee house alone and may attract a wider range of species.
Placement and positioning
Correct positioning is as important as construction. The three requirements are south or south-east facing orientation for morning sun that warms the tubes early in the day, height of 1-2 metres above ground which is eye level or slightly above, and firm stable mounting so the house does not rock in wind – movement prevents bees from locating their own tube reliably.
Place the bee house near a pollen and nectar source – within 50-100 metres of flowering plants that bloom from March onwards covers the main nesting season. The wildflower meadow is one of the best companion plantings for a bee house – the dense mix of open-structured flowers provides accessible pollen throughout the bee nesting season from spring through late summer. A muddy patch of bare soil near the bee house is valuable for red mason bees, which use mud to seal cells – a small tray of damp clay or a persistently bare muddy patch within a few metres is worth maintaining deliberately.
Annual maintenance routine
Bee houses need annual maintenance to remain effective and hygienic. In autumn, when all adult activity has ceased, bring the bee house indoors or into an unheated shed for winter storage – this protects developing cocoons from extreme cold and predation by woodpeckers, which learn to raid bee houses where tubes are accessible. Return the house to its outdoor position in late February or early March before the first red mason bees emerge.
Replace tubes every 2-3 years as a minimum regardless of condition – old bamboo accumulates parasites and fungi that harm developing larvae even when the tubes look externally clean. If using paper tubes, replace annually. Keep sealed tubes from the previous season in a separate small box next to the house so adults can emerge normally in spring without being confused by proximity to an active nesting site.
Do not store the bee house in a heated room over winter. The warmth signals spring to developing bees and causes them to emerge too early, before pollen is available. An unheated shed, garage or outbuilding keeps temperatures cold enough to maintain correct dormancy through winter. Cocoons stored at ambient indoor temperatures from October onwards will fail to survive to the following season in usable condition.
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