All About Mason Bees

by | Mar 15, 2022

Mason bees are gentle, hard-working pollinators and they are wonderful creatures to have in our gardens! Mason bee cocoons are available now, but many folks are unsure how to settle them into their yards. When we held our last public spring seminars (pre-Covid!) we were fortunate enough to have Loren Muth join us for a session on Mason bees. Loren raises Mason bees and has a wealth of knowledge and experience working with them. As we head into spring, we wanted to share some of his tips for success with you.

Minter Country Garden - All About Mason Bees--white blooming plant

Mason bees are active during spring, from February to June, which means they’re great for pollinating fruit and berry crops. The first bees to emerge in spring will be the males, followed by the females. The lifecycle of  mason bees takes place throughout the whole year. While their only active period is spring, their offspring prepare for their short-lived emergence all winter.  

Minter Country Garden - All About Mason Bees--mason bee home

Placing your Mason Bee House 

 The first step to keeping Mason bees is to purchase or build yourself a bee house. Once you have this you’ll need to find an ideal location. Mason bees prefer to hang about 6-7 feet  above the ground, ideally this will be sheltered by an eave, shed, garage or other overhang. Mason bees like to be sheltered from the elements, but you do want the location to receive adequate sunlight. The house should receive south to south-eastern sun exposure. If you can’t provide your bee houses proper south or southeastern sun exposure, ensuring the house receives at least ample morning sun will encourage them to start foraging earlier. 

Minter Country Garden - All About Mason Bees--mason bee in home

Trays and Tubes

Once you’ve placed your bee house it’s time to think about outfitting your house with nesting tubes/trays. Some houses will come with pre-designed nesting trays and bamboo/paper tubing. The style of bee house you purchase will determine the method you use for cleaning and maintenance. Ideally use solid block housing with removable rolled paper tubes. This aids in cleaning debris, parasites and anything else that may get into your house. If you’re rolling your own, a pencil or pencil-sized dowel works to roll the tubes around. Keep in mind paper tubes will need to be replaced annually. If you decide to make your own house ensure your holes are about 5/16” diameter and about 6” deep. This helps ensure a good female to male ratio in each tube.    

Minter Country Garden - All About Mason Bees--crocus flowers

The next thing you’ll need to consider is ensuring your bees have a good source of food and adequate nesting materials. You’ll need to provide forage flowers within a 300 foot radius of their houses. Native, non-hybrid plants with staggered blooming that produce a lot of pollen and nectar are recommended. For nesting materials, all you need to do is provide a source of mud or clay, and the bees will do the rest. 

Once you have everything set up you’ll need to get your bees! Cocoons are normally available at the end of February, but they should not be released until the time is right. Until then, you can store your cocoons in a fridge, but it should not be a frost-free fridge (if that is what you have, place damp towels or a tray of water nearby to increase humidity).

When to Release the Bees

Climate in the Valley in spring can be fairly variable. Here’s some rules of thumb to ensure your bees survive spring: 

  1. Ensure about 1/4 of your garden is in bloom or the buds on flowering trees are ready to burst into bloom.  
  2. Ensure daytime temperatures are consistently 12°C. 
  3. Ensure any chances of frost are low.  
  4. Stagger putting your cocoons out by two weeks between each placement. 

Note: March 1st is generally a safe time to put your bees out depending on the average temperature, just take a quick look at the forecast before you do!    

Thank you for your helpful tips, Loren!