Leaving the Leaves

Finding a Middle Ground

We have been conditioned to believe that we must tidy up our gardens in the fall, cut back our perennials, and remove the fallen leaves. “Leave the leaves,” ecologically minded gardeners will cry. Others will say, “it’s not that simple.”  What’s a homeowner to do?

It’s true that leaving the leaves is a more economically and environmentally friendly approach to fall clean up. Leaves provide free mulch that helps retain moisture and protect plant roots in winter, and they replenish the soil as they decompose. Leaf litter is also critical to sustaining many of the pollinators you have tried to attract by adding plants like milkweed, cone flower, and bee balm to your yards.

Many butterflies and moths overwinter in the leaf litter.  If you gather up and throw out the leaves, you will likely be destroying many of the valuable pollinators you attracted during the growing season.  Native bees will also lay eggs in the hollow stems of plants like Joe Pye-Weed, so leaving these stems standing through the winter will support pollinators as well. Leaving the leaves also sustains a host of small critters that, in turn, provide food for larger animals such as birds and turtles. Leaf litter is an important part of the local ecosystem. Your garden beds, especially naturalistic or wooded area plantings, will love it.

To be sure, you should remove any plant materials that are diseased. Clean off any drains and remove leaves from walkways and places you prefer a neater look. Some perennials, such as peonies, will not be happy with several inches of leaves (or any other mulch) covering their crowns.  Your lawn will also not appreciate your leaving a thick layer of leaves on it.  Solutions for the lawn include mowing the leaves into the lawn, creating a leaf pile in a corner of your yard and allowing them to compost, or shredding them and spreading the leaf mulch in your garden beds.

As a compromise, if you want to support pollinators but prefer a tidy look, you can postpone leaf removal until the spring.  Simply wait until the temperature is reliably above 50 degrees, and then remove the leaves.  You will lose the free fertilizer benefit of letting them decompose into the soil, but you will have supported the pollinator population through the winter.

Source and Further Reading 

Fialkoff, Anna.  Leave the leaves. Wild Seed Project

Simisky, Tawny.  Hort Notes 2020 Vol. 31:9. Questions and Answers University of Massachusetts Amherst.  Center for Agriculture, Food, and the Environment UMass Extension Landscape, Nursery and Urban Forestry Program.

Vieira, Joann.  Hort Notes 2019 Vol. 30:8. Questions and Answers University of Massachusetts Amherst.  Center for Agriculture, Food, and the Environment UMass Extension Landscape, Nursery and Urban Forestry Program. 

Wheeler, Justin.  Don’t spring into garden cleanup too soon! Xerces Blog. 4 April 2017.