Pugnacious leafcutter bee
(Megachile pugnata)
A native bee commonly found in Chicago yards
Photo by Nick Dorian, Garden scientist
DIY Bee Homes
Pollinators are crucial to the health of the planet, helping with everything from the food we eat to the cycle of life. You can welcome pollinators such as bees into your yard by making a native bee home.
Mason bee (Osmia lignaria)
Did you know that native bees are better and more efficient pollinators than honeybees when it comes to fruit trees? Honeybees carry pollen in sacks on their hind legs, which doesn’t always make it to the stigma of the flowers they visit (anthers are where the pollen grains are picked up; stigma is where they are deposited for successful pollination). Mason bees (Osmia lignaria) carry pollen all over their bodies, which means that the pollen has a greater chance of reaching the stigma for proper pollination. One mason bee can pollinate as many flowers as 100 honeybees.
Mason bees pollinate a wide variety of flowers, in addition to fruit trees, with a particular emphasis on the rose family. They are generalists though, so they pollinate many types of vegetables too. If you are interested in growing fruit trees and vegetables in your yard, you may want to attract and support more mason bees.
Are you avoiding bees because they sting? Another reason to invite mason bees into your yard is that they are nonaggressive. Honeybees and bumblebees may defend their nests if disturbed, so bee skeps—or domed hives—are usually located on larger plots of land, not in typical backyards. Male mason bees do not have stingers, and the females only sting if they are trapped, so there is little reason to fear them.
How to Make a Bee Condo Block
Give native bees a helping hand by installing a homemade nesting block in your home landscape. Affectionately called “bee condos,” a little wood, some glue, and a drill with various bit sizes is all it takes to invite nature’s best pollinators to call your garden home.
Rot-resistant cedar or redwood are excellent materials to use, but recycling-minded gardeners can reuse whatever wood they have or reclaim, as long as it has not been treated with chemicals. Untreated wood is readily available at big-box stores and lumberyards. Ask them to cut blocks to length with an angle at one end for the roof.
Unless you’re talking nectar, bees aren’t fussy. They want shelter from the elements and a suitable place to nest. A block of wood 4 inches wide, 6 inches deep, and a foot tall is a good size. Or glue together several foot-long pieces of 4- by 6-inch boards with predrilled holes.
A bee condo creates a community, and drilling holes in different sizes encourages diversity. Alternating rows of holes that are five-sixteenths in diameter with rows that are three-eighths is recommended. Or, have more than one condo with different sizes of holes to attract different kinds of bees. Holes of all sizes should be about 5 inches long.
The finishing touches are adding an overhanging roof and drilling a hole in the back to make installation easier. Make the project extra fun for kids by letting them decorate the outside of the bee condo.
Mount the bee condo near flowers or trees in a sunny location that’s protected from wind. It can be placed anywhere between 3 to 15 feet off the ground. A spot near eye level—or at different eye-levels if you’re making more than one—will make it easier to know if the holes are being used.
After several years, redrill the holes and soak the nest block for 30 minutes in a solution of water and bleach. Rehang the bee condo after it’s dry.
How to Make a Mason Bee Home
Supplies:
- Clean, 15-ounce metal can
- Phragmite reed tubes (6 inches long)
- 2¼-inch-wide bark ribbon
- Cling floral adhesive (or similar putty tape)
- Duct tape (camouflage blends in well)
- Scissors
- Rubber bands
Instructions:
Step 1: Fill the metal can with as many reeds as you can tightly pack inside. Ensure the open ends of the reeds are facing out. Use duct tape to encircle the parts of the reeds that are sticking out of the can.
Step 2: Cut three strips of bark ribbon to wrap around the can and the duct-taped extension. Use bits of cling adhesive to adhere the bark ribbon to the can in three sections, so it is completely covered.
Step 3: Cut two 8-inch-long pieces of bark ribbon and duct tape them together along the long edge. Place this over the top of your can as a roof. You want to create a small gable that overlaps ½ inch over the end of the tube to keep the reeds dry when it rains.
Step 4: Use bits of cling to adhere the roof to the house. If needed, further secure the roof with two rubber bands. Place the completed bee house in a fairly protected area, against a flat surface with a southwest exposure. Placing the house high up ensures that bees will not mingle with people when entering and exiting their new home. Leave your bee house out all summer and you should find mason bees filling the tubes with larvae.
For information about storing and incubating mason bees for next year, visit seedsavers.org.