How to Build Orchard Mason Bee Nests

Due to Colony Collapse Disorder, many areas of the country are experiencing a decline in their honeybee population. A decline in honeybees and other social bees means a decline in pollinators, which can have an adverse affect on the gardener’s vegetable production. Maintaining a beehive is hard work. In addition, many people find the number of bees associated with a hive overwhelming for urban and suburban settings.

The solitary bee, the Orchard Mason Bee (Osmia lignaria), is the ideal solution to the problem of pollination. Orchard Mason Bees are extremely gentle and will not sting unless threatened by rough handling. They are also more efficient pollinators than their cousins, the honeybee. An Orchard Mason Bee’s pollination success rate is 93%-99% as opposed to the 3% pollination success rate of honeybees. As a result, it takes fewer Orchard Mason Bees to fully pollinate an area than it takes honeybees to pollinate the same area.

Attracting and maintaining an Orchard Mason Bee population is quite simple. Make sure you have plenty of flowers in your yard, build a nest, provide a mud collection site, and you will probably have success in attracting Orchard Mason Bees. Below are instructions for a simple Orchard Mason Bee’s nest.

Supplies

• Untreated 4X4 lumber
• 2X4 lumber
• A pole cap
• 1/4 -5/16 inch drill bits
• drill
• Screws
• Screwdriver
• Saw

Instructions

1. Cut your piece of 4X4 lumber to the size you want for your nest.
2. Drill 1/4 -5/16 inch holes into the side of the lumber. Make sure the holes are far enough apart so that they don’t break into each other. Note: It is important to make sure the holes are free of debris and bits of wood shavings. Orchard Mason Bee’s prefer clean holes and will not use holes that are obstructed.
3. Screw the 4X4 nest onto a long piece of 2X4 to create stability (you may skip this step if you will be attaching the nest to trees, fences, or decks.
4. Attach the pole cap to the nest to help shed water.
5. Place the nest in a location that receives good early morning sunshine.

Ideas and Suggestions

• Dig a shallow hole and keep it damp to provide the bees with mud for their nests. The best kind of mud is a clay mud – too much sand or too much organic material is unsuitable.
• Make sure the nest gets plenty of sunshine and is protected from too much rain.
• Make sure you have lots of flowers in your garden. Particularly useful for attracting the bees are native flower varieties. Check with your local county extension office to find out what native flowers can be grown in your yard without becoming invasive.
• 1/4 inch holes will yield male bees and 5/16 inch holes will yield female bees.
• The bees prefer their nest to be at least 2-3 feet off the ground.
• More than one bee will use the same nesting house. A female Orchard Mason Bee can lay up to sixty eggs in her lifetime.
• If the holes pass through the board, use a piece of plastic (cutting up an old bottle works well) and tack or staple it to the back of the nest.
• An alternative to a stand-alone nest is simply to drill holes into the end of a 4X4 and find a sheltered site with morning sunlight and place the nest there.

Suppliers

To purchase Orchard Mason Bees or to buy pre-made Orchard Mason Bee Houses contact Knox Cellars: Native Bee Pollinators or Beediverse: The Mason Bee People.