In addition to cool nights, pumpkins and vivid tree colors, autumn brings the back-breaking job of raking leaves.
I have good news, though: You can most likely leave the leaves on the lawn, in the landscape beds and definitely in the vegetable garden.
The best method for dealing with fallen tree leaves is to mulch them. Mow over leaves with a mulching mower if you have one. A regular mower will work, too, but the shredded leaves will be coarser than if they are chopped with a mulching blade. Allow the leaf pieces to fall back to the turf, where they will break down and return nutrients to the soil.
If leaves get too thick over the lawn, they will prevent sunlight from reaching the grass, so the best method is to mow frequently. Grass will die if it goes too long without sunlight.
In landscape beds, leaves can be left around the plants as mulch. When trying to decide how many leaves are too many, think of them in the same light as any other kind of mulch. Mulch piled against the base of plants (especially trees and shrubs) holds moisture that often leads to decay. If leaves pile up, spread them through the flower bed, or rake them to the lawn.
Leaves can also be removed and chopped through a chipper/shredder before re-distributed on the lawn and garden. Leaf tissues break down more quickly after they are chopped.
I know the next question: “How many leaves are too many?”
Luckily, Michigan State University conducted research to try to answer this question. We still do not know the maximum number of leaves, but we know you can leave a lot. In the study, leaves were approximately 6 inches thick piled on the grass — officially 1 pound of leaves per square yard of lawn. After five consecutive years of mowing leaves with a mulching mower, the grass was just as healthy as grass that had been raked.
The only place I do recommend raking your leaves from is the curb line or ditch if you have one. Leaves in the street and in ditches wash into storm drains, streams, rivers and lakes. When leaves clog drain openings, they increase the likelihood of flooding in your neighborhood. Leaves that make their way into the streams and rivers begin breaking down in the water where they release nutrients. Increased nutrients in the water can lead to algae growth that depletes oxygen and may be detrimental to aquatic life.
OK, sometimes the leaves are too much for your little lawn or garden to handle. You will have to rake, but you can at least compost the leaves and return the good, broken-down stuff to the garden next year.
To compost, pile the leaves in the backyard with the deadheaded flowers, weeds from the garden, fruit and vegetable scraps from the kitchen, coffee grounds, etc. Commercially available compost bins will keep your composting site looking a little more kempt, if you prefer, but are not a requirement for composting.
The final option, for those with inadequate space for leaves or compostm depends on your location. Lawrence residents can place their leaves in compostable bags or cans for yard waste pickup. Other area residents should check with their city or county officials to determine whether they have a site where leaves and yard waste can be deposited instead of paying to send it to the landfill.
Now, what will you do with all time you would have spent raking leaves?
— Jennifer Smith is the Horticulture Extension Agent for K-State Research and Extension — Douglas County and can be reached at 843-7058.