Posted 23 November 2011. Applied Turfgrass Science.
Should You Rake, or ‘Leaf’ Well Enough Alone?
Source: University of Arkansas Press Release. www.uaex.edu
Fayetteville, Arkansas (November 18, 2011)--Wind, weather and time are sending thousands of leaves cascading down onto your lawn. Should you rake, mulch or wait? That depends on your lawn, said Mike Richardson, professor-horticulture with the University of Arkansas Division of Agriculture.
“Every year, I get lots of questions from my neighbors about mulching leaves, raking them every week, or just waiting until they all fall to clean them up,” he said. “Unfortunately, there is no one-size-fits-all recommendation.”
Want a quick answer? Look at your grass.
In the northern half of Arkansas, most lawns that have lots of trees and leaves are planted with cool-season grasses, like tall fescue or bluegrass, which grow actively in the spring and fall. Central and southern Arkansas boasts more St. Augustine or centipedegrass, warm-season grasses that do their growing from late spring through early fall before going dormant.
So, in other words, cool-season lawns should have a minimum of leaf litter so that the grass can take advantage of its best growing period. Warm-season lawns can afford to have leaves pile up because they are already entering a dormant period.
Now, mulching or raking? That’s a little trickier.
“We don’t have a lot of local data [on which method is more beneficial], but studies show that mulching leaves back into the lawn causes no negative effects on the turf and can even return some nutrients and organic matter into the soil,” said Richardson.
“That can have long-term positive effects on the lawn.”
While mulching can be helpful, there is only so much leaf litter a lawn can handle. “I’m not sure there’s a firm number, but if you start seeing an accumulation of 1 inch of litter at the soil surface and it isn’t rapidly decomposing, it would be a good idea to rake the leaves,” he said.
If you choose to mulch, do it just after the leaves have fallen. This will help speed decomposition of the leaves, said Richardson. Decomposition slows as cooler temperatures set in.
“Waiting until the end of the fall to mulch all the leaves will not only be hard on the mower, but it will also lead to a thicker leaf layer, since decomposition will be significantly slower,” he said.
When mulching, set the mower at a relatively high height, such as 3 inches, so there is a larger canopy for the mulched leaves to hide in. This keeps the lawn from looking cluttered.
Eventually, some raking will have to be done.
“If you rake, remember to put the leaves into compostable bags for pickup, or dispose of them at a facility where they will be composted and can be returned to the soil,” said Richardson. “It is never good business to dump leaves into a landfill or into an area where they could lead to nutrient release into surface waters as they decompose.”
Many of Arkansas’ larger cities have curbside pickup of lawn and leaf debris. Once picked up, the material is composted and can be used by residents the following season.
But what if there are too many leaves to mulch or rake in an afternoon?
“There might be a few kids around the neighborhood – or around the house – who want to make some spending money,” he said.
For more information on lawn and leaf management, visit www.uaex.edu or contact your local county Extension agent.