How to Build Healthy Solitary Bee Hotels & Nesting Blocks

Thank you for taking the time to learn how to build healthy nesting material for your mason bees and leafcutter bees.

Healthy nesting material is nesting material that can be opened, inspected, and cleaned. At the beginning of every season, clean nesting material should be placed out for your bees.

Many people build bee hotels using bamboo or logs with holes drilled into them. While these may look attractive, they can actually harm developing bees because they cannot be opened and cleaned. Over time, they can harbor pests and diseases such as pollen mites, chalkbrood, Houdini fly larvae, and mono wasps.

If you host mason bees, there are three important steps you should follow every year to keep your bees healthy.

1. Place Clean Nesting Material Out in Early Spring

Always begin the season with clean nesting material. Starting with clean nesting trays, cardboard tubes, or blocks helps reduce disease and pest pressure from previous years.

2. Remove Nesting Material at the End of Spring

Adult mason bees only live about 6 to 8 weeks. Once nesting activity has ended, remove the nesting material and store it in a protected location.

Leaving nesting material outside all summer exposes developing bees to predators and parasites such as mono wasps, beetles and birds.

3. Open All Nesting Material and Harvest Your Cocoons

In the fall, open all nesting material and harvest the cocoons.

Cleaning cocoons removes pollen mites, parasites, and disease organisms that can affect next year’s bee population. Clean cocoons lead to healthier bees and better pollination in your garden.

We Clean or You Clean

At Rent Mason Bees, we offer two options.

We Clean

If you choose our Rental Program, simply send your nesting material back to us in the fall. Our team will harvest, clean, inspect, and store your bees until the following spring.

This is a great option for gardeners who want healthy bees without having to clean cocoons themselves.

You Clean

If you prefer to clean your own bees, we provide educational guides and resources to help you successfully harvest, clean, and store your cocoons.

Both options can produce healthy bees when done properly.

Want to Build Your Own Nesting Blocks?

People love building their own mason bee houses. If you would rather skip the building process, visit our store to order sterilized nesting blocks and exceptionally clean, healthy bees.

If you decide to build your own nesting material, here are some helpful guidelines.

Best Nesting Hole Sizes

Mason Bee Nests

• 8 mm diameter
• 6 inches long

Leafcutter Bee Nests

• 6 mm diameter
• 3 inches long

Providing the correct tunnel size helps female bees produce healthy offspring and improves nesting success.

Building Your Own Stacking Trays

Our stacking trays are made from alder wood.

If you build your own trays, be sure to use untreated wood. Do not use pressure-treated lumber or wood that has been treated with chemicals. Developing bees are sensitive to chemicals and residues that may be present in treated wood.

Building Emergence Tubes

Our PVC emergence tubes are made from:

• 1-inch PVC pipe
• 6 inches long
• Two end caps
• One 8 mm hole drilled into one end cap

These tubes provide a safe place for cocoons to emerge in spring while helping protect them from weather and predators.

Black Shelter House Specifications

Our standard black shelter house is designed to protect nesting material from rain and excess moisture.

Dimensions

• Width: 4 inches
• Height: 8.5 inches
• Depth: 8 inches

Materials

• Cedar
• Plywood

Color

• Black

If your shelter house needs repainting, we use: Rust-Oleum Painter’s Touch 2X Flat Black General Purpose Spray Paint.

Healthy Bees Start with Healthy Habitat

Providing nesting holes is only part of the equation.

The long-term health of your mason bees and leafcutter bees depends on clean, removable nesting material that can be opened, inspected, and cleaned every year.

By following these simple practices, you can help protect your bees from pests and disease while supporting stronger pollinator populations in your garden.

Whether you choose to clean your own bees or participate in our Rental Program, healthy nesting material is the foundation of successful solitary bee stewardship.

Visit Rent Mason Bees to order healthy bees, sterilized nesting blocks, nesting supplies, and bee houses designed with bee health in mind.