Using bee boxes on your farmland is a great way to provide nesting habitat for solitary bees.
There are many species of wild bees in the UK that are called ‘solitary bees’, because unlike honeybees and bumblebees, they do not live in social colonies but make individual nest cells for their larvae.
Some of these species nest in small tunnels or holes in aerial locations; and so an artificial nest box stocked with suitable tubes can provide important nesting sites.
These hairy bees can be similar to honeybees in appearance, and include bees such as leafcutters and mason bees but also tiny, hairless yellow-faced bees. Females will stock their individual nests with nectar and pollen and then seal it, leaving the young to fend for themselves. Solitary bees are excellent pollinators and will provide substantial pollination services to your farm.
You can buy ready made bee boxes or to make your own see instructions below:
Boxes should be located in the driest, sunny and sheltered position possible, ideally south facing. Avoid surfaces that appear to be damp or that are covered in moss. Attach the box either to a farm building, a post or construct a free standing box with a raised base at least 50cm above the ground to prevent rising damp.
Ideally boxes should also be located as close as possible (within 1km) to large areas of pollen and nectar forage of at least 2ha; and sited away from bird feeders and bird nest boxes. See our advice on the creation and management of forage.
Make sure that you put your box up by the end of February or as soon as it is built – the longer it’s up, the more chance it has of attracting visitors and species like the Red Mason-bee will start using them by March.
Solitary bee boxes should be made from wood. Metal and plastic are unsuitable materials as they may cause the contents of the nest to overheat or encourage condensation making conditions damp and unsuitable for bees. The type of wood used is not critical but hardwoods, such as oak and beech, will outlive soft wood, such as pine. The thickness of the wood should be at least 15mm to provide sufficient insulation and to prevent warping.
Boxes should be 50cm x 50cm and 20cm deep, open fronted but backed and constructed of untreated timber and no wood preservatives should be used. The box must be weatherproof and should have small drainage holes in the floor. It is important that the inside of the box doesn’t get too cold or warm and that the box is durable.
It is better to nail your box together rather than gluing it (remember to use galvanized/stainless steel nails to stop rust) as this allows water to drain.
The box should contain at least 4 individual compartments which are tightly packed with a different material in each compartment. Suggested materials are:
- Drilled hardwood blocks (holes 7cm long, with mixed diameter 5-12 mm but with 50% at 12mm)
- Sections of bamboo stem (15-25cm long, 5-25mm in diameter)
- Reed stems (Phragmite stems may be sourced from a local wetland with landowner permission and then dried) or paper drinking straws 7-8mm diameter
Top tip – Do not put a ledge on the box bottom or top, or in between the individual compartments box as this is not necessary and may aid access to a predator!