Outdoor enthusiasts enjoy supporting pollinators in many ways including placing bee hotels in their gardens. Better design such as using red cedar for the hotel, nesting material sized right and replaced on schedule will support healthier bees.

Many bee hotels sold online work better as cute garden decor or creative gifts. Many are too shallow or are built as a one-size-fits-all BUG hotel. Don’t take me wrong, the designs are really creative. But if you want to support healthy bee populations, it is best to use RESEARCH-BASED INFORMATION from multiple universities to design the hotel. We have collected the latest research below.

Hotel Design (The Outer Box)

• Build bee hotels for bees, not other insects. Mixed insect habitats can lead to food and territory competition, as well as invite predatory insects that eat bee larvae. Stick with a box design and nesting materials made for bees.
• The size and shape can vary, but make the box deep enough for nesting material that is over 6″ in length. A good depth would be 8″.  Keep each hotel small, containing no more than 100 nesting tunnels (a few dozen tunnels per box works best).
• Several smaller hotels throughout the garden are better than a single large hotel. Parasites and fungus are a common problem in poorly managed hotels and can quickly spread throughout a shared space.  If that happens, you may need to discard all nesting material in the whole box.
• Choose natural, untreated wood such as red cedar, which resists rot and pests.  Avoid plastic hotels or PVC tubes that can become overrun with mold. Boards should be 3/4″ thickness to best protect bees from large predators like birds and rodents. Untreated pine may also be used but should be primed and painted inside and out.  Choose an exterior latex paint with a low VOC rating of <100.
• After cutting boards to size, fasten the box together using waterproof glue, such as Titebond T3, and galvanized staples.
• Roof design should slope to shed rain and overhang the front by 2″, to help protect the nesting material from weather.
• A drainage hole or two in the bottom of the structure will aid in removing trapped rainwater.
• Place the finished bee hotel in a bright, sunny spot about 5 feet off the ground. Mount it on a fence post or the side of a building, with the openings facing east or southeast. This lets the morning sun warm the bees early in the day. At the same time, it helps to pick a spot that gets some afternoon shade.
• If birds and rodents start to destroy nesting material, a metal screen made from hardware cloth or similar can be attached to the front of the box.
• Though they can last for many years, boxes should be inspected for signs of parasitic mites, mold and fungus. Replace or sanitize them as needed.
• To sanitize an infested box, use one part household bleach to three parts water. Soak the box thoroughly and let it dry before adding fresh nesting material.

Nesting Material

• Use materials that mimic what bees use in nature such as untreated wood, hollow stems, bamboo and hollow reeds. All tubes should be closed on the back using the natural node or joint of the stem. Avoid using plastic straws which develop mold and cardboard tubes which are prone to predators.
• If drilling holes in wood, use wood that has aged for several months and is dry. Properly dried wood is easier to drill, has less splinters and is resistant to splitting.  Bees prefer maple and other hardwoods.
• Tunnel depth should be around 6″ or more. The mother bee will lay female egg(s) in the back of the tunnel and fill the remainder of the tunnel with male eggs. Adequate depth will ensure both males AND females.
• Tunnel diameter should vary between 3.2mm – 12.7mm (1/8″ – 1/2″), to allow for different sizes in individuals and species. The majority of tunnels should be 9.5mm (3/8″). Position the tunnels 3/4″ apart.
• To help bees locate their tunnel easily, materials can be staggered in length and vary in shape. Sometimes a few blocks are painted, too.
• After young bees leave the nest in spring, they may return to the same tunnel that they emerged from. While that is fine one time, used nesting materials should be replaced after one to two years. An easy is using an “emergence box”, that allows the young adults to fly out but makes it hard for them to return. Otherwise, remove the used nesting materials quickly after the bees have emerged in early spring.  If you see bees entering the tubes, they are already starting to build new nests.

Check out this bee hotel design from NC State https://content.ces.ncsu.edu/how-to-manage-a-successful-bee-hotel/appendix-4-building-plans-for-a-simple-bee-hotel-shelter

Emergence Box

• How to use an emergence box: In winter, remove the nesting materials from the bee hotel. Not all tunnels will be sealed to the end, some are only partially filled but still contain eggs. Place the nesting materials in an emergence box. A simple shoe box works fine, just punch a 1/2″ hole through the side near the top. Keep the box out of the weather and in a cold, dry place like a storage shed.
• In early March, refill the bee hotel with fresh nesting material.  Locate the shoe box near the bee hotel to encourage the young bees to move into the hotel.  Arrange the nesting materials so that the young adults can easily leave their chambers and make their way to the single exit hole. While waiting for bees to exit, keep the shoe box off the ground and cover the top with plastic to protect it from rain. After all bees have emerged, discard the used nesting material and the shoe box.

Remember to limit (or eliminate) pesticide use on flowers when bees are active!

If you want more information about bee hotels, let me know. Thanks for reading!