Making a Home for Solitary Bees
If you already have solitary or mason bees in your garden you can consider yourself very fortunate. They are invaluable for pollinating fruit and vegetables and go about their daily routine without any desire to sting. If you don't yet have any of these modest creatures living locally it may well be that there is nowhere for them to nest. To change that you can buy some elegant bee houses, a more rustic pollinating bee log or make something similar yourself:
Take any old piece of timber. An old fence post is ideal. It does not matter if it's old and battered. In fact this will look more like the natural, weather worn wood that many solitary bees nest in. Avoid wood that has been treated with preservative.
Use an electric drill and a standard set of drill bits for wood. Drill a range of sizes up to 10mm diameter. Make sure that there is a good variety of hole sizes, particularly in the range 5-8mm diameter. Drill lots of holes.
Make sure the holes are drilled slightly upwards into the wood. This prevents rain water from collecting in the borings. Don't make the borings too steep though!
Dig the post into the ground, or attach it to a standing post with wire ties. If you are using blocks of wood just put them anywhere in a sunny position.
Other ways to make homes for solitary bees: Any type of cavity is likely to prove attractive to solitary bees. Collect a bunch of old, dry, hollow stems of plants like bramble and hogweed. You can also use bamboo canes or even drinks straws.
Put them into an old baked bean can, or something similar. Melt some candle wax in the bottom of the can, then stuff it full of hollow stems, or straws. You'll know you've got bees when some of the ends are filled in.
Or go the whole hog and build an insect hotel.
For more information about solitary bees, try the RES