ST. PAUL, Min. — We are in the middle of autumn and the piles of leaves are growing.
Mark Hawkinson is working outside his home for the second day in a row and at least has a plan for all the leaves that keep falling on his property.
“I just blow what I can off our driveway, and then I lightly rake the leaves on the lawn, and mulch the rest,” Hawkinson said.
It is an effective, if repetitive, cleanup process. Hawkinson estimates he will remove about 80% of the leaves and mulch the rest. Removing leaves creates a green lawn, but doing the opposite can create one.
“We always want everything to be neat and tidy, and it doesn’t necessarily have to be that way,” says Jon Trappe, a turfgrass lecturer at the University of Minnesota. “There may be some benefits behind having a little more clutter.”
What are the benefits of mulching leaves for our lawns?
“We recommend mulching the leaves because we can return nutrients that are important to our lawns or to the trees themselves,” says Trappe.
Most tree leaves contain about 1-3% nitrogen, which is the most important element for plant growth.
“We’re essentially getting some free fertilizer for our lawns,” Trappe said.
It’s free and all-natural, instead of manufactured, store-bought fertilizer.
“We have a lot of flower beds, so we don’t rake them out,” Hawkinson said.
Why would we want to leave leaves around our trees or plants?
“They retain moisture and prevent it from evaporating into the atmosphere,” says Trappe.
Like wood chips, leaf mulch can help soil retain moisture around flower beds and tree trunks, regulate soil temperatures and suppress weed growth. If you plan to put leaves around your garden beds or shrubs, make sure the mulch is 3 to 4 inches deep. It will eventually decompose and fertilize the soil.
What are the disadvantages of mulching?
“Eventually you may get to a point where you have too much left on the surface after mowing,” says Trappe.
If you use a mower to mulch the leaves in your yard and barely see any grass afterward, it’s time to remove some. Mulching only the leaves can increase the risk of snow mold in the winter.
“It slows the greening of the grass as it comes out of winter dormancy, but in some extreme cases it can actually kill the grass,” says Trappe. “If the grass dies, it needs to be replanted.”
As Hawkinson continued to work in his garden, he noticed that the leaves were considerably heavier than the day before. There was a rain shower last night. Wet leaves do not mulch well and are much harder to remove.
“Waiting for them to dry will be helpful for several reasons,” Trappe said.
An excuse to postpone an autumn chore and make the job easier at the same time.
Jeff Wagner
