Are there adverse grass lawn effects by leaving fallen tree leves as a mulch

Asked November 14, 2015, 2:46 PM EST

Are there any adverse grass lawn effects by leaving the typically fallen tree leaves in late fall (October through November) as a mulch on the Kentucky Bluegrass lawn? The leaves that have fallen are from cottonwood, ash, and crab trees. We live in Fort .Collins, Larimer County, Colorado.

Larimer County Colorado

1 Response


There are actually many benefits to mulching the leaves into the lawn after they have fallen. But the leaves do need to be broken up by a mower--leaves left whole can lead to disease problems in the spring.

There are two excellent blogs on the subject...we strongly encourage people to mulch the leaves into the lawn and as long as you can see some green following mulching, the leaves will break down. There is also some incredible research on the subject from Purdue and Michigan State--one study found that mulching leaves into the lawn will reduce weeds.

Here are the two blogs: and