Take spring cleaning advice with grain of salt
Gardeners hanging out on social media these days are telling people to wait to spring clean flower gardens until temperatures are regularly in the 50s. They say you shouldn’t cut back the stems of last year’s perennials until that time. By doing this, you provide stems to support cavity- or stem-nesting native bees.
Sixty to 70 percent of native bees nest in the ground. Perhaps you have come across one of these nests while mowing. This is not fun, especially when they fly up your shorts. The other 30-40% nest in cavities or cut stems.
While the recommendation sounds logical, it’s not based on science and is not quite accurate. In addition, it’s not practical for everyone.
Leaving perennial plants from last season standing in the garden over the winter is not a bad practice. Many of our perennials provide seed and habitat for birds, and many of them provide winter aesthetic interest.
However, if you have a large garden or are a commercial landscape manager, you may not have time in the spring to clean up the entire garden. Plants such as hosta and others that provide no aesthetic or food for birds can be cut down in the fall.
Leaving the sturdy stems over the winter can be beneficial for the cavity-nesting native bees. However, you don’t have to wait until the temperature is in the 50s to clean up the garden for them. You can do it any time in the fall or later winter.
The key to providing a place for these bees to nest is to leave some of the stems standing. Don’t cut everything back. And when you cut the dead stems, remove the blooms and leave the rest of the stems at varying heights, between your knees and hips.
This opens the stem for the cavity nesters. They won’t nest in a stem if there is still a flower head. They prefer a cut stem to easily tunnel down to create the nest. Eventually, the new growth hides these stems, and the bees complete their life cycle in the stem.
My perennial bed is quite large and a couple of weeks ago I took my trimmers and cut almost everything back except for a few plants that had sturdy stems.
In other words, I left some stems for the bees and cleaned up the rest of the bed.
I am excited to check these stems during the season to see if the bees indeed used them for nests. I am hoping that by adopting this practice I will attract some of our native bees.
There is so much misinformation on social media that I encourage readers to question what you are reading and inquire about the research on some of these statements.
I understand that people want to support pollinators, and this is great. But by understanding their habits and life cycle you will do a much better job.