Why are leafcutter bees not nesting in my bee house?
For first-time leafcutter bee raisers, this is our most common question in the summer.
First, please be patient. It takes time for the leafcutter bees to emerge from their cocoons and it can take up to two weeks to see leafcutter bee activity at your bee house. Female bees have to find flowers, the right kind of leaves, mate, and then they return to nest; and they can also be away from the bee house for up to 30 minutes while gathering pollen, nectar, or leaves. Bees also begin building their nest at the very back of the nesting hole where they are hard to see while inside the nest.
Next, please check to see how many bees have emerged from their cocoons. Leafcutter bees use temperature cues to tell them to emerge and they need a minimum of 75F daytime highs to emerge. Leafcutter bees also emerge from the flat end of their cocoons and this can make seeing open leafcutter bee cocoons difficult.
Here are the questions that we ask our customers to help them determine any troubleshooting areas. Unfortunately, sometimes we do everything right and since leafcutter bees are wild creatures, they can decide to nest elsewhere for reasons unknown.
Troubleshooting questions
- How is the weather? Leafcutter bees purchased from us are incubated and arrive ready to emerge and they start to fly when daytime highs above 75F. Bees are cold-blooded and poor weather will limit their flying activity. Male bees take shelter on nearby plants and sometimes use the bee house for shelter.
- Is your bee house in a good location? Leafcutter bees like to sunbathe in the morning and this is why we recommend installing your bee house in a morning sun location. In warm locations, we recommend installing your summer leafcutter bee house in a spot that gets afternoon shade. If your yard is shady, consider installing your bee house in a spot that gets the most exposure to sun throughout the day, even if this means that the bee house gets afternoon sun. If you need to move your bee house, do it at night so any nesting bees have time to reorient to their new surroundings in the morning.
- Does your yard offer the right kind of leaves? Leafcutter bees won't nest if they can't find tender leaves nearby. Some known favorite leaf sources are hosta, rose, lilac, bougainvillea, buckwheat, redbud trees, pansy, and viola. If these plants are not nearby, try adding pea, bean, or smooth-leaved strawberry plants to your garden near your bee house.
- Do you have enough open flowers nearby? Each female mason bee can visit up to 2,000 flowers per day - take a look at your open flowers. Remember that female leafcutter bees can fly for 4-6 weeks and you should offer a variety of flowers that are blooming while the bees are flying. Leafcutter bees are generalists but they also like flowers in the legume family (peas, beans, lupine) and open-faced flowers in the aster family like daisy, sunflower, fleabane, etc.
- Are birds or other critters bothering your bee house? A sign that a woodpecker or squirrel was interested in eating your bees is when you find your loose nesting holes strewn on the ground. Install our Bird Guard to the front of your bee house.
- Do you avoid lawn care chemicals? Solitary bees like leafcutter bees are pickier than social bees when it comes to where they live. Solitary bees only fly in a 300-foot radius from their bee house and some lawn chemicals can harm or deter bees from nesting. Avoid chemical applications before and while bees are nesting. Be aware that chemicals applied in your neighbor's yard may drift into yours and deter your bees.