A pollinator hotel by Don Pendleton at MOFGA's Farm and Homestead Day in 2019. Credit: Courtesy of Don Pendleton

Building a pollinator hotel is a great way to make space for pollinators on your property, especially if you live in an urban environment. Pollinator hotels provide a home for solitary bees and a place for other pollinators that live alone to build their nests.

The structures are designed to assist native bees as opposed to honeybees: about 30 percent of the 5,000 native bee species in North America build nests in a variety of aboveground cavities or tunnels. These bees do not live in a hive or make honey, but they are much less likely to sting than honeybees because they aren’t defending a colony.

Don Pendleton, buildings and grounds assistant for the Maine Organic Farmers and Gardeners Association, is a pollinator hotel architect. He holds a workshop about building pollinator hotels — from tiny, simple bundles of sticks to veritable insect Shangri-Las — at MOFGA’s annual Farm and Homestead Day (which is next scheduled to happen in 2021). He explained that making a pollinator hotel helps counteract some of the damage we do to pollinator habitats during spring cleaning.

“In the springtime, we want to clean up all the time,” Pendleton said. “One of the worst things we do is clean the leaves up. The pollinators nest under the leaves — where they nest is the eyesores you don’t want to see. By making a designated space for them, you’re not getting rid of it and you manage it better.”

As an added benefit, Pendleton said that building a pollinator hotel will change the way that you look at bugs in your yard.

“It brings you closer to nature,” Pendleton said. “When you start to work with them and put these nest boxes out, you get over the fear of the bugs and that loating of them. I call it getting over the ‘ooh-factor’ of the bugs.”

Step 1: Gather materials

A pollinator hotel by Don Pendleton at MOFGA’s Farm and Homestead Day in 2019.

At the most basic level, a pollinator hotel will provide a series of small, deep holes for solitary bees to nest in. Pollinator hotels can be as simple or as complicated as you want, from a bundle of bamboo or block of wood with holes drilled into it or a house-like structure with blocks and bundles of varying sizes.

There are a few rules for choosing materials for pollinator hotels. Dry, clean and untreated wood that won’t splinter is preferable, though you can sand sharp edges. Splinters in the entry holes could be fatal to a native bee and may deter them from entering the hole.

“A mistake people make is they tend to use softwood because it’s easier [to drill],” Pendleton said. “If you drill into cedar or pine, you notice it leaves a lot of splinters. Bees are not going to go in there because it’s too much of a hassle. Find wood that will drill clean, [like] oak, maple [or] most of your hardwood.”

Pendleton said to look around and see what you have in your yard, especially hollow stems that are closed on one side. You can even use invasive species from your annual spring yard cleaning.

“Japanese knotweed makes perfect pollinator spaces,” Pendleton said. “They’re natural. The insides are smooth. People are like, ‘Yes, just take it.’ I have asked agricultural experts and they said [it] will not spread when you use dry stalks.”

For one of his first pollinator hotels, Pendleton bundled a bunch of Japanese knotweed together and hung it from the eaves of his house. He originally used duct tape, though he said he is now trying to use twine and other compostable materials in its place.

Step 2: Bundle and drill

A pollinator hotel by Don Pendleton at MOFGA’s Farm and Homestead Day in 2019.

If you are using a series of sticks or dowels, you need something that will bind them together tightly. Pendleton said that duct tape works best, but he is trying to find organic alternatives, like tightly-wound twine.

“I couldn’t find a way to keep them tight and snug without using the duct tape,” Pendleton said. “I just have the hardest problem using the duct tape knowing that it’s a toxic, non-organic material and that’s why we went away from that. If you can find something that binds them up tight, that is the best.”

To attract as many species of bees as possible, drill holes of varying sizes, or use a variety of hollow plants. Native bees vary greatly in size; the bigger the bee, the larger the diameter and greater depth they require for their nest hole. Pendleton said that he makes extra efforts to attract blue orchard bees, which prefer holes about the diameter of a No. 2 pencil.

Do not drill all the way through the block, and if you are using hollow plants, close them off at one end. Make holes fairly deep in order to encourage bees inside.

“You have to think like a bug,” Pendleton said. “When the queens lay their eggs, they lay a long row of eggs. If you have a very long hole, they put more queen eggs in there. The holes have to be deep, bigger than a normal drill bit. ”

Also, resist the urge to paint your blocks or bundles. Natural wood is more attractive to bees.

Step 3: Site your hotel

A pollinator hotel by Don Pendleton at MOFGA’s Farm and Homestead Day in 2019.

As with a regular hotel, location also matters. The house should be a minimum of three feet off the ground, so keep that in mind if you are building a frame. Keep them in a partially sunny spot, so the sun can warm the bees but won’t overheat them. A roof-like top will also help keep rain off of the guests in your pollinator hotel.

“Keep them out of the wind, out of the direct sun [and] you try to make them so that the birds don’t get in on them,” Pendleton said. “You can put them in trees as well, but if you put them in a tree you need to have a cover on them.”

Pendleton said the best place to put them is under the eve of a house, where birds and predators can’t reach it. The bees are not apt to sting, so it shouldn’t pose a threat to the human tenants inside.

The timing of placing your hotel outside also matters. Native bees nest in the spring, so it is best to set everything up in early spring. Now is not too late, but get your pollinator hotel out there as soon as possible.

“It’s the time right now if you can get them out there,” Pendleton said. “Different bugs will have different times, [and] we’re having a late season this year.”

You can also have multiple bee hotels in your yard, but be sure to space them out. Pendleton said that he has pollinator hotels all throughout his orchard at home.

“I can go in the orchard when it’s blossomed and I can feel the trees vibrate,” he said. “I have these nest boxes all over the place.”

Step 4: Wait and observe

A pollinator hotel by Don Pendleton at MOFGA’s Farm and Homestead Day in 2019.

By the summer, you will be able to tell if you have guests in your new hotel. The bees will create “doors” to the hotel out of mud and leaves, which indicates that a female bee has laid an egg inside. After the bee hatches, it will eat a supply of pollen until it is ready to break through the seal and fly away. Keep a variety of flowers and plants in your yard for pollinators to enjoy.

At the end of the summer, if the holes are still sealed, though, nature may have had other plans for your buzzy guests. For example, a parasitic insect may have noticed the hole is sealed and drilled a small hole through the seal and eaten the larvae or the bee Or, if you don’t notice an entry hole in the seal, a fungus may have killed the bee. Resist the urge to spray the hotel if this is the case, because it could harm the other pollinators living there.

Pendleton said to be patient with your pollinator hotel. It could take time for local pollinators to find your hotel and figure out that it is a good place to nest.

“Don’t expect results right away,” Pendleton said. “It might take a couple years.”

Still, it is a fun project as you are conducting your spring cleaning to get rid of some of the debris around your yard. If you build it, they will come.

“Don’t worry about perfection: just go and do it and put it together and experiment,” Pendleton said. “Have fun with it. See what happens; you might be surprised at the results.”