Gloucestershire Beekeepers' Association

You’d expect to read about providing nesting sites for birds, but did you know you can provide them for bees too? There are more than 250 kinds of bees in Britain, including mining bees, which burrow into the ground, and mason and leaf-cutter bees which nest in hollow plant stems or dead wood.
Wild bumblebees are valuable pollinators of crops, garden plants and wild flowers. Their pollination service is especially use­ful where few honeybees are working, perhaps because hives have not been brought in, or because poor weather prevents bees from leaving the hive, or on crops with deep-throated flowers, inaccessible to shorter-tongued honeybees. Today, with honeybees being badly affected by varroa, the role of bumblebees as pollinators is even more important.
Sadly, a quarter of our native bees are endangered, and even familiar bumblebees are disappearing, reducing the number of pollinators for crops, wild flowers and garden plants. So our gardens are fast becoming a lifeline to many insects that cannot find nest sites and food in intensively–farmed countryside.
Over the past 30 years, several spe­cies of bumblebee have disappeared from arable regions of Britain. 
On sunny days in the Spring you may see a large Queen bumblebee flying slowly, to and fro, close to the ground. She is looking for a nest site (a hole in the ground which may have been used by a mouse or bumblebees last year) which is dry and full of soft moss and feathers. Home to a bumblebee is a warm, dry, insulated and well-drained space about the size of a football, containing some soft dry bedding material, because most bumblebees do not collect their own nesting materials. Bumblebees can be encouraged to nest by creating nest boxes. These can be extremely simple and purpose-built. Place them in a spot where no-one will disturb them.

A simple version can be made from four bricks placed on edge with an entrance gap, and covered with a tile. Don't forget to add dry bedding to the nest.

Another version is a large terracotta flower pot (not a plastic one which sweats) with the open end buried at an angle into the ground.  Make sure that rain cannot get in.

If you are good at woodwork then you can make a box 25cm cubed made from untreated timber 2cm thick. A 2cm hole near the base is cut for an entrance. The top can be made out of clear plastic to allow observation which is covered with a tile or piece of slate to protect it from the weather.  This box must be raised from the damp ground on bricks.

You can use old clean bedding from pet mice, gerbils or hamsters or use dry moss and leaves. Even torn up tissue paper will do.