Your Mason Bees
The when, where, and how-to for
Southwest Washington and Northwest Oregon
February
Now is the time to get things ready. If you haven’t already done so, open your straws or tear apart boxes, clean your cocoons and refrigerate in the crisper drawer of your refrigerator. Check every week to make sure they are not drying out or getting moldy. If you don’t harvest your cocoons you may choose to skip this step. Its purpose is to keep pests and diseases out of your yard. If you are going to paint or coat the outside of your box to weather protect, do it now. Make sure the smell has dissipated before you put in the cocoons (about 2 weeks). Choose a sunny protected location to place your box. Under the eves of a building, facing east or south, 3-5 feet above ground is perfect. Keep it out of direct wind.
Find a good source of mud within 20-50 feet of the box, if possible. Dig a hole 6-12 inches deep and pile the mud beside the hole. The bees will select dryer or wetter mud depending on rain amounts. If you don’t have silty-clay type mud, you may need to gather some from another source. Good soil, in this instance, is not a good thing.
March-April
Bloom happens at different times depending on weather and your elevation, but this is the month for most blooms to start. Check your yard (and your neighbor’s) for bloom within 300 feet. Check the weather for a few warm, sunny days (50-55) and if your bloom is ready, the bees can go out. Open the bee container and place on top of the straws in the box. Make sure the mud is ready. Male bees should hatch in a couple of days and females a couple of days after. If the weather turns cold, soak a cotton ball in sugar syrup and place inside the box. Bees don’t always go back to the box, sometimes they hang out nearby. Check the cocoons in a couple of weeks to look for “holes” in the cocoons. If you need to hold your bees over until April, just keep checking them for dehydration or mold and follow the same instructions. Holding bees for longer will result in bees not being as viable.
March Pollen and Nectar sources
Alder, andromeda, quaking aspen, balsamroot, blueberries, buttercup, cherry, chickweed, black cottonwood, crocus, currant, blue elderberry, elm, filbert, forsythia, hazelnut, heath, miner’s lettuce, dead nettle, fiddleneck, vine maple, big-leaf maple, photinia, plum, pussy willow, salmonberry, skunk cabbage, sweet gale, skimmia japonica, Oregon grape, willow, windflower.
April Pollen and Nectar sources
Alder, apple, Oregon grape, bearberry (kinnikinnik), birch, black cottonwood, blueberries, buttercup, cascara, cherry, clover, chickweed, currant, dandelion, dead nettle, dogwood, Douglas fir, blue elderberry, elm, fiddleneck, holly, honeysuckle, huckleberry, lupine, miner’s lettuce, oak, Oregon ash, pear, photinia, pine, plum, quaking aspen, salmonberry, skunk cabbage, sweet gale, western crabapple, willow.
April-June
They should be out and working. After a few weeks you can take a flashlight and look into the holes at night. You should see bees and/or mudded over areas. If about 2/3rds of the holes have filled, you can make or purchase more straws or add another box to keep them laying in the area. You can stand within a couple of feet during the day and watch them and they won’t bother you. When activity stops, the bees are done and have probably died off. Females only live about 6 weeks and the males live about 2 weeks. What you have left in June is next year’s crop of mason bees.
May Pollen and Nectar sources
Alder, apple, Oregon grape basswood, bearberry, birch, black locust, blackberry, bog laurel, brassica family, cascara, clover, chickweed, cotoneaster, currant, dandelion, dogwood, grass, hawthorn, holly, honeysuckle, horse chestnut, huckleberry, lupine, madrona, maple, meadowrue, miner’s lettuce, mullein, oak, Oregon ash, pea, pear, plantain, plum, poppy, raspberry, rose, salmonberry, Scots broom, serviceberry, skunk cabbage, spiderflower, cherry, western crabapple.
June-August
You have some options at this point:
- Leave everything in place. The advantage is that it’s no work. The downside is that parasites and predators can get at the eggs and stored food. You can reduce this by placing a some kind of netting over the entrance and securing it.
- Remove the straws and/or box, to a protected area placing them face up or at least at the same facing level they were when outside. An outbuilding works fine. Encase the box and/or straws in fine screen or mesh bag. The eggs will develop into larva and then spin cocoons during the summer.*
This is how we do it.
September-February
You have options here also:
- You can leave everything in place, whether you did option 1 (leaving the box and straws outside) or option 2 (placing the straws/box in a cool protected area).
- You may decide to bring the straws/box into a protected area because of the weather if you didn’t do so during the summer.
- You can place the straws/boxes in the refrigerator anytime until March. The advantage is the bees will not be subjected to heating and cooling and will be in better shape by spring. Harvesting the bees before you put them out in March will allow you to see what you have and be able to destroy pests and any diseased bees.
- You can harvest the bees about 1st of October and place them in the refrigerator. The advantage to this is keeping the bees at a level temperature and removing parasites and diseased bees.*
Refrigerating bees has several advantages, but it can be tricky. Try to keep your bees in the vegetable crisper drawer where the humidity is higher. Today’s frost free refrigerators can dry out bee cocoons. Also, mold can grow on the cocoons, and although it doesn’t hurt them, it can be alarming. Temperatures should be about 35-40 degrees, humidity should be about 50-70%.
*Preferred way of processing bees.
More sources for mason bee information
snohomish.wsu.edu
xerces.org
homeorchardsociety.org
gardening.wsu.edu
crownbees.com
sare.org/Learning-Center/Books