Here's why leaving the leaves helps bumble bees. When cold weather hits, each recently born and mated bumble bee queen will find a place to overwinter as her colony dies off. She needs to survive the winter alone in a hibernation state if she's going to start a new colony in the spring. She's vulnerable. Research is lacking on what types of overwintering sites bumble bees prefer and how often they survive. But, queens are known to overwinter in underground burrows in loose soil and leaf litter.

As summer comes to a close, most native bees are near the end of their lifecycle. Bumble bees leave their colonies. New queens (gynes) search for nectar and pollen in late-blooming flowers and eventually find a sheltered place to hibernate through the winter. Solitary bees overwinter as pupae or larvae inside cocoons. Avoiding pesticides and dedicating a spot in your yard for a leaf and brush pile can help provide a safe space for these important pollinators. 💛🖤 | Wisconsin Department of Natur