Most store-bought bee hotels are toxic to native bees, here’s how to build your own

Eager to give nature a helping hand and to encourage more pollinators, many people have been buying bee hotels from the shops and adding them to their gardens.

But they are often surprised and disappointed to find that no native bees, or even any other bugs, use the newly offered abode.

We spoke to Clancy Lester, a native bee ecologist from The University of Melbourne, about what the problems are with most readily available store-bought bee hotels and his tips and tricks for building your own bee hotel that is healthy and attractive to native bees.

Imported bee hotels are toxic to native bees

“Most bee hotels available in stores are too toxic for native bees to use because they are usually imported and get fumigated at border biosecurity,” said Clancy.

Fumigating wooden imports is very important to prevent new pests or diseases from entering the country where they could wreak havoc on our native flora and fauna. However, some fumigants leave a residue that makes imported hotels toxic to native bees, so they won’t be able to move in once the hotel is established in your garden.

Clancy said that treated woods often add to the toxicity of store-bought bee hotels.

“Treated woods have toxic chemicals like copper, chromium and arsenic solution forced into them to protect the wood from insects and microbes.”

This is another deal-breaker for native bees. Varnishes and paints are also a problem. If you make your own DIY bee hotel, you also have to avoid imported wood and bamboo due to fumigation and avoid locally sourced wood that is chemically treated.

Lastly, commercial hotels are often built with the wrong cavity dimensions - the holes are frequently either too large or too shallow to house native bees, which are much smaller than invasive European honeybees.

If purchasing a bee hotel, Clancy said “opt for Australian-made hotels by knowledgeable distributors.”

But by making your own, custom-built hotel from locally sourced materials, you can ensure your hotel is bee-friendly - and it’s super fun and easy.

Catering to diverse tastes

Australia has over 2,000 species of native bees, and they use a variety of nest types. Fortunately, there are three styles of hotels that cater to the majority of tastes.

Hardwood hotels

Many native bees nest in holes in native hardwood like eucalyptus, but different species prefer different sized hotel rooms. Masked bees (Hylaeus) like 3-5 mm holes, while leafcutter bees (Eutricharaea) often like ~7 mm holes and resin bees (Megachile) like 4-8 mm holes

Cut sourced hardwood to 200 mm lengths and drill holes of various diameters (3-10 mm) to depths of at least 100-150 mm.

“Using drill bits bigger than 10 mm is useless for native bees and may only attract spiders, cockroaches or small reptiles,” says Clancy.

Reed, bamboo and pithy stem hotels

Cavity nesting bees love locally sourced dead, pithy flower stems, hollow reeds and untreated bamboo that have a cavity opening less than 10mm wide.

Cut them to 200 mm lengths close to a node (so one end is sealed), bundle them up, cram them into PVC pipes or old tin cans, and hang or place them securely off the ground (around eye level).

Clay block hotels

Around 70% of Australia’s native bees nest in the ground, including solitary bees like the blue-banded bee (Amegilla).

Create a mix of clay and sand and pack into something like a concrete besser block or durable container. Poke small holes using a pencil or stick and place the hotels horizontally on the ground in an area with plenty of sun. Make sure to place clay block hotels next to bare patches of unmulched ground as some ground-nesting species will prefer to make their own homes.

Design for comfort

When building a bee hotel, the comfort of the residents should be top of mind.

Just like people, bees enjoy the sunlight. Avoid placing your hotel on the south-side of buildings, which are often shaded in Australia, or in darker areas of your garden. Bees also like to wake up with the sun, so face hotel openings towards the north-east to delight them with a sunrise.

Bees also enjoy a dry home. Provide shelter for your hotel with a roof that keeps out the rain while still allowing plenty of sunlight to shine through. When drilling holes into hardwood, angle them slightly upward to prevent water from pooling at the bottom. And be sure to steer clear of plastic or metal tubes for the hollows, as these can trap condensation or heat up too quickly in the sun.

Location, location, location

The best hotels have delicious restaurants close by and bee hotels are no different.

“Plant native wildflowers, such as native daisies (Asteraceae) and flowering shrubs and trees such as myrtles (Myrtaceae), native peas (Fabaceae), and proteas (Proteaceae). Some exotic plants like salvia and lavender are good food for blue banded bees. Also limit pesticide/herbicide use on open flowers or spray at night if you have to,” says Clancy.

The Wheen Bee Foundation has a great planting guide for the bees likely to visit your local area.

Don’t forget to clean up for the next guests

At the end of winter, before the weather warms up, your guests should have packed up and left the hotel (signified by a small exit hole on a once-capped hole). You can easily tidy up with a pipe cleaner to remove any debris, dead cells, and spider webs.

“After a few years, your native bee hotel might need to be replaced,” says Clancy. But that’s a great opportunity to improve your design to encourage more bees to visit.

Native bees face a range of threats to their existence, that’s why it’s up to us to create pockets of habitat to support our local pollinators. Download our how-to guide today to start building your own bee hotel.