The Bee & Bee in your garden or how to help solitary bees

Solitary bees are important pollinators but often overlooked in favour of the bigger and more obvious bumblebees and honeybees. We thus thought it can’t do any harm to bring them into the spotlight here on our urban pollinator blog.

There are more than 200 species of solitary bees and you can see them buzzing around in your garden as early as March. Solitary bees do not live in large colonies and do not have any worker bees (with a few exceptions). Each female solitary bee is fertile and inhabits a nest built by herself. There are two different types of nests; ground nests build by sweat bees, (Halictids) and alkali bees (Andrenids) and cavity nests build in hollow reeds, twigs or holes in wood by leafcutter bees and orchard bees (e.g. genus Osmia).

Andrena fulva, a ground-nesting solitary bee

Each female constructs a series of cells, each with a food source (pollen and nectar packed into a ball) and a single egg that is laid on top. The nectar and pollen for each cell is gathered in several foraging trips, and this is why solitaries are such useful pollinators. Depending on the species, the cells are lined with various materials, including leaves, petals, mud or body secretion. When the entire nest is complete it is sealed off and the next nest started.

Depending on the species, solitary bees have one to several generations a year. In species with just one generation per year, it is usually the pupae or larvae that overwinter in the nest and emerge in spring the next year. The first bees to emerge are normally the males. They will often wait near flowers to mate with the emerging females. The males will then die and the females will search for nesting places.

A little Red mason bee male emerging from a nest

If you want to learn more about different solitary bees have a look at our other blog posts about the   Hairy-footed flower bee (Anthropora plumipes), the Tawny mining-bee (Andrena fulva), the Red mason bee (Osmis bicornis), the Harebell carpenter bee (Chelostoma campanularum) and the Ivy bee (Colletes hederae).

A female Hairy-footed flower bee visits Pulmonaria flowers

A shed is a good place for solitary bee "hotels"

If you want to help solitary bees you can provide nesting places in your garden. Ground nesting bees normally find their own nesting sites in loose and often sandy soil in sunny places with short grass. But you can really help the cavity nesting bees if you provide them with hollow reeds, canes or twigs stuffed tight in a wooden box, tube or tin or with wooden blocks with holes drilled into them (try to drill holes with different diameters, ranging from 2 mm to 10 mm). You can also cut bamboo canes of different sizes in pieces, bundle them together and hang them up (make sure you cut them before a join so they are closed at the back).

Soon the first solitary bees will arrive to nest in your "bee hotel"

Of course you can also buy a commercially available bee hotel but make sure you buy one with holes with different diameters to attract a range of different bee species.

Mason bees like bee hotels attached to south-facing house walls

It is very important to hang the bee hotel somewhere warm and sheltered about 1-2 m above the ground, a south facing wall is often ideal. And don’t be afraid of hanging the bee hotel close to your door or window as solitary bees do not sting.

Solitary bees tend to forage in the vicinity of their nest. If you don`t have already lots of bee friendly flowers in your garden or allotment you can further encourage them by planting these. To find out which plants are considered bee friendly, just visit a plant nursery or garden center on a sunny day and buy the plants which are most visited by bees and other pollinators. Also have a look here and here for more ideas of what to plant.

Plant lots of flowers for your solitary bees

Below you can see some examples of bee hotels we found in the gardens we have sampled for pollinators.

A bee palace, but try to put it in a location as sunny as possible

If you add more holes you will attract even more bees

A bee hotel made from a wooden block with holes drilled in.

A bee hotel with enough space to accommodate other insects as well