How 'Rented' Solitary Bees Can Help Your Garden

It’s cleaning time for pollinator houses as people get ready for next year’s bees.

Based in Bothell, Washington, the company Rent Mason Bees rents two species of bees across the U.S. Farmers, teachers, and nature fans set up nesting material in their yard and then release solitary bees that don’t have a queen or a colony.

In October, the company cleans and sterilizes cocoons and nesting blocks. Washing them removes predators like pollen mites and Houdini fly larva that can be harmful to bees. Then the nests are prepared to be shipped out, starting in spring.

It’s a tedious process to ensure the bees and their surrounding ecosystems stay healthy, says Thyra McKelvie who runs the company’s pollination program.

Mason bees are “sweet little bees,” says McKelvie, who talked to Treehugger about solitary bees, why people rent them, and how they help the world around them.

Treehugger: What is a solitary bee?

Thyra McKelvie: Solitary pollinators are one of mother nature’s best pollinators because of the way they pollinate. They have tiny hairs on their bodies called scopa. They are clumsy little bees and belly flop onto the flowers, which collects loose pollen all over their bodies. They can visit up to 2,000 flowers a day dropping pollen as they go from flower to flower. Honeybees meticulously collect pollen on their legs and don’t drop much because they have to carry it back to their hive. This results in an astonishing difference of pollination rate between the two bees. Mason bees pollinate 95% of the flowers they land on. Honeybees pollinate 5%.

There is no queen and they don’t make honey. Each solitary female bee finds her own nest, gathers her own food and each one lays all her own babies. Without a queen or hive to protect, they are docile and not aggressive. You can stand right next to a nesting block and watch them work. The males don’t have a stinger and the females have a small one, but never use it as a defensive mechanism to protect them. The only time you could get stung is if you squish one and their sting doesn’t have any anaphylactic venom, so bee allergies are not a problem.

When they lay an egg, it grows into a larvae that eat the pollen loaf mom left and then spins a silk cocoon. Just like a butterfly, it will hibernate in that cocoon all summer and winter and then emerge the following spring as a full-grown bee. Mason bees only lay about 15 babies in their lifetime whereas a honey bee queen can lay up to 2,000 babies a day. 

What was the impetus behind the creation of Rent Mason Bees? 

We get asked all the time “Rent bees? How does that work?” It may be a bit confusing, but hosts release bees into their yard and habitat and rent the nesting material. The rental part is that we do all the maintenance and cleaning of the block and bee cocoons. Many people don’t realize that this is a critical step when hosting solitary bees. Just like honeybees need maintenance, solitary bees do too. But with our rental program, you don’t have to do any of the maintenance. Your bees will lay babies in your nesting block and then send the block back and we’ll clean and remove all the predators. Our bees are sorted by region, so your “baby bees” will be all clean and ready to release the following spring.

Who are your typical clients? Backyard homeowners or farmers (or both)? 

We work with backyard gardeners, school teachers who use our kits to teach kids about pollination, and people who want to make an impact in their area by helping release more pollinators and enrich their habitats. 

What is in the rental bee kit? When they are returned, how are they returning the next generation of bees? 

We provide two types of solitary bees. spring mason bees who emerge when temperatures reach 55-plus degrees and summer leafcutter bees who emerge when temperatures reach about 75-plus degrees. All kits will include a black house or shelter, nesting block, clay for mason bees, flower seeds, and about 60 bees snug in their cocoons. When bees emerge they will fly off and find natural holes in their habitat or lay eggs in your nesting block. In September, nesting blocks are returned and we harvest and clean all the cocoons and blocks. 

How are the bees shipped and how do people determine what kind to get?

We ship our bees using USPS Priority mail so that bees arrive quickly. They are protected by their cocoons and safe for transportation. Mason bees don’t do well in really hot weather, so we don’t sell bees to certain states.

What is the setup like and what upkeep is necessary?

Solitary bees are very easy to set up. Simply hang your black house in a sunny morning spot, usually south-facing. Insert the nesting block, put the white tube on top of the block, and pull the tape off the hole. The bees will emerge once temperatures warm up and they’ll crawl through the hole and find food. 

There needs to be a mud source nearby for mason bees, so we provide you clay to mix with your soil. The only maintenance would be to make sure your clay stays damp and sticky. It’s a great job for a child to “water the clay” and stir with a stick. Since you are renting the nesting block there is nothing you need to do throughout the season. We’ll notify you when to swap blocks (switch from mason to leafcutter bees) and you’ll send the blocks back in September. The rental service is where we do all the cleaning and maintenance of the bees and blocks.

Because these are spring/summer pollinators, why is this an important season as you clean the blocks and take orders for next year? 

Many people don’t realize the importance of cleaning mason bees every fall. Predators, such as pollen mites, Houdini fly larvae, chalkbrood, and many other predators need to be removed from the nesting block in order to stop the population growth of predators. One of the big things we try to teach mason bee hosts that raise their own bees, you can’t leave your nesting material out all year round. Mason bee blocks are removed at the end of spring and stored safely in the garage or shed. Summer predators can harm your bee population. 

What questions/concerns do potential clients have? 

The No. 1 question we get asked is, “Why rent?” We realize that some people want the entire year experience of caring and cleaning mason bees, but for those who want to support bees and get their yards pollinated but not worry about cleaning all the mites and predators off cocoons, sterilizing the nesting blocks and storing over winter, they rent from us and we do all the maintenance for you. The second question we get asked is “Do they make honey?” No, they do not.

What are the benefits to the ecosystem and to the individuals who take part? 

Solitary bees are incredible pollinators. Whenever they touch a flower, they are strengthening the tree or plant, which makes them grow stronger and bigger, resulting in better soil and cleaner air.