By Katie Drewitz & Adam Austing, University of Minnesota Extension
Raking leaves is one of those fall chores that you likely aren’t thrilled about doing, especially if you have an abundance of trees. It seems that this time of year the question that always arises is if it’s really necessary. The short answer to that question is that it depends on your situation, but let’s try to be a little more specific than that.
The first thing you need to consider is how much of your turf grass is covered in leaves and leaf debris. Your lawn can likely handle a 10-20 percent leaf debris coverage, but any more than that can cause significant issues. If your lawn is completely covered, the turf grass would be smothered next spring and therefore unable to grow. A thick covering of leaves can also promote snow mold diseases which can kill off your lawn as well.
If you have a less significant coverage, one great option is mulching your leaves. Mulching and leaving the leaf debris can have many advantages to your soil and lawn. Some leaf types have been shown to reduce weed seed germination when mulched into a lawn canopy (maples and others). The leaves of some particular tree species (legumes like honey locust and others) might actually add a significant amount of nitrogen to lawns because these species fix nitrogen from the atmosphere so higher leaf nitrogen contents in these leaves is possible. More information on these concepts can be found at www.extension.umn.edu. You need to consider the final percentage of the lawn that is covered after mulching to avoid the issues mentioned above.
If mulching is not an option due to the volume of leaves in your yard, you can consider using a bagging attachment on your mower to pick them up, or you can rake your leaves. Composting your leaf material is a great idea. Leaves and grass clippings both make excellent additions to your home compost pile. If you have had any disease issues in your trees or other plants with leaves, do not add those leaves to the compost pile, and do not leave them on your lawn, mulched or whole. Many bacterial and fungal disease can stick around on the leaf debris and then re-infect your plant next year.
If you have additional questions about your trees, leaves or lawn, you can visit the University of Minnesota Extension website, or reach out to (763) 682-7381 or firstname.lastname@example.org.