Ask Extension: Is it too early to cut back perennials for pollinators?

Ceratina bee on a cut stem.
Photo: Colleen Satyshur, UMN Bee Lab

Q: Is it too early to cut back the dried stems on my perennials? I don't want to harm the bugs/bees that may have made a home in them over the winter.

A: From a plant health standpoint, it's fine to cut back perennials when the snow has melted and plants are accessible. However, from a pollinator health standpoint, leave some stems intact for use by stem nesting bees. 
Here is how to handle this task: 

• Stem nesting bees can lay eggs in perennials stems. So as you're cutting perennials back, place the cut stems somewhere in your yard out of the way so any bees nesting in the stems get a chance to emerge. When these bees emerge this summer, they will need new nesting spots. 



Photo: Colleen Satyshur, UMN Bee Lab

• Leave some stems about 8" above the ground so they can form new nests. The rest of your perennials can be cut down to the ground.  

Photo: Julie Weisenhorn, UMN Extension

It's a good idea to remove the rest of your plant debris. It is possible that some fungal spores may be present on the foliage that you will not want in your gardens this season.

Composing things would be the best solution however you could just dispose of them in trash bags. In doing all of this, be mindful of new shoots that may be coming up. 

Authors: Elaine Evans, Extension Educator and Bee Researcher, Julie Weisenhorn, Extension Educator - Horticulture