In last month’s newsletter, we mentioned the key aspects of creating a bee-friendly environment. This month we’re going to dive deeper into creating artificial nests for native bees. Placing nests in your yard is similar to hanging up a bird house. There is no guaranteed occupancy, but following a few basics can help to increase your chances. Also, keep in mind that many solitary species are only active for a few weeks a year and can be rather elusive. If you don’t see a bee, it doesn’t necessarily mean they aren’t using the space! Look for evidence of nests, like mud in wood nests or debris at tunnel entrances.
Creating small nests (5 to 10 holes each) of varying sizes is the best way to cater to a wide variety of bees and avoid attracting predators and pests. It can also help you to determine which areas of your yard are preferred.
- Use logs, branches or a preservative-free block of wood.
- Drill smooth holes between 3/32” and 3/8” in diameter, and at least ¾” apart.
- Holes should be about 16cm deep and be perfectly horizontal or angle slightly towards the entrance. Do not drill completely through your block, the tunnel should only have one entrance.
- Holes can be lined with parchment or wax paper. Use a knitting needle or pencil to roll them.
Stem bundles can be made using the same basic guidelines. You can use any hollow plant material, though bamboo is often easiest to find. Either secure a few stems with string or stuff them into a tin can, old flower pot or similar container.
For placement tips read our article on habitat creation.
Ground nests are suitable for many solitary and semi-social bee species, but can be a tricky to construct successfully at home. It may be easier to spend the season observing your space to see if there are already areas where bees are nesting. Look for sunny spots with ant-like tunnel entrances. If you spot some, do your best to leave these areas undisturbed.
If you want to try and create a ground-nesting area, it’s best to start small and track success before tackling a larger area, especially on small city lots. A large container or small raised bed is a simple start, just make sure the soil is at least two feet deep. Different species have different soil preferences, so you can experiment with what you have or replace or amend soil. Loose or well-draining soils are generally preferred, but be sure to speak to a garden center before adding sand to your soil, if not done properly it can create a concrete-like structure.
Bumble Bee Nests
Creating a nest for bumble bees can be as simple or creative as you please. Bumble bees in the wild seek out a cave-like spaces, usually underground and they especially love old mouse homes with soft bedding. To create a similar space, aim for the following as a baseline:
- Use preservative-free lumber or other wood to create a box with the interior dimensions of approximately 18x18x18cm. The lid should removable for cleaning but fit tightly when in use.
- Line the inside, bottom of the box with chicken wire and create small holes on the upper sides of the box to allow for ventilation.
- Cover the bottom with raw cotton (not cotton balls), yarn, or dry straw for bedding.
- Create an entrance with ¾ inch hole on one side, near ground level.
- Replace bedding each year
Bumble bees can be fussy nesters so it may take a few seasons before you have occupants. This simple wood box is just the beginning of nest options; the nest can be buried with tubing for a tunnel entrance, have hinged lids for a viewing window, constructed using a clay pot, the options are endless. There are a great many resources and articles that can help you to experiment in your own backyard.
All nest types should be installed outside in the very early spring, just before the first flowers bloom. For tips on where to place nests read last month’s article on habitat creation and enjoy your new garden guests!