Supporting wild bees in the garden: targeted habitat creation for biodiversity

The essentials in brief

• Wild bees rely on specific pollen sources from native plants, as they are highly specialised, unlike the honeybee.
• Creating nesting sites must consider a mosaic of clay soil, deadwood and pithy stems.
• June is a crucial month for supporting the summer generations of wild bees through a continuous supply of flowers.

Habitat design in June

Many wild bee species are actively flying in June. If you want to encourage wild bees in your garden, a general wildflower strip is not enough. Many species show a strong bond with specific plant families, a phenomenon known to biologists as oligolecty (specialisation on a few plant species).

To build a stable food web, the combination of providing nesting sites and a staggered succession of food sources is essential. The Red Mason Bee (Osmia bicornis), for example, requires nesting sites as early as spring, whereas the Wool Carder Bee (Anthidium manicatum) now relies on visiting Lamiaceae (mint family plants) in June.

Specialisation of native wild bees

Practical tips for a wild bee hotspot

1. Create patches of bare ground: About 75 per cent of all wild bee species nest in the ground. Remove the turf in sunny, sparsely vegetated areas of the garden to expose sandy or loamy soil. This allows species such as Mining Bees (Andrena) to dig brood tunnels.
2. Integrate deadwood: Leave sections of hardwood standing vertically in the ground or drill holes into logs lying on the ground. Important: Make sure the holes are drilled across the grain to prevent splitting, and clear any splinters from the entrances.
3. Select plants by flowering phases: Avoid double-flowered ornamental varieties from garden centres. Use native wild plants instead. A mixture of Viper’s Bugloss (Echium vulgare) for early-season bees and Bellflowers (Campanula) for specialised Resin Bees covers a wide spectrum of species.
4. Cut back stems in late summer: Only cut back dried perennial stems such as Mullein (Verbascum) or thistles in the following spring. These pithy stems serve as protected overwintering sites and nesting tubes for many wild bees.

Focusing on nature-friendly maintenance

Avoid fertilisers and pesticides entirely. Synthetic herbicides, in particular, harm soil fauna and destroy the essential supply of wild herbs. A structurally diverse garden with transition zones ranging from lean meadows to thickets offers the highest density of nesting opportunities. Ensure that no invasive species, such as Canadian Horseweed (Erigeron canadensis), displace native food plants. Native wild plants should always be the primary goal of your garden planning, as they have developed a co-evolutionary adaptation to our wild bees.

Frequently asked questions

Why are honeybee-friendly plants not always ideal?

Many wild bees are highly specialised and require the pollen of specific plant families. Cultivated varieties often offer no nectar or nectar that is inaccessible to them.

When is the best time for nesting aids?

Nesting aids should be available all year round. June is the ideal time to add to your supply of pithy stems and open ground areas.

Do wild bees need a water source?

Yes, a shallow dish with stones to act as a landing platform serves as a vital drinking spot for many insect species on hot June days.

Main article: Nature gardens in allotments: step-by-step to biodiversity