"Why is it necessary to rake leaves off the lawn?" is a question that many of us have asked. Some of them (from red maple trees, for example) look quite pretty lying on the grass, do they not? Moreover, they are, undeniably, natural (and that is supposed to be a good thing, is it not?). If your neighbors are out there raking leaves all the time (or, if not actually raking them, then using blowers, etc. to clean them up), you may well wonder whether they are simply guilty of being neat-freaks.
It's a Matter of Lawn Health, not Tidiness But there is a sound reason behind raking leaves pertaining to lawn health; it is not simply an aesthetic choice. You have probably heard that lawns, too, have to "breathe," and that they can be smothered if a thick layer of unshredded leaves is left on top of them over the winter, causing problems such as snow mold. That is true, but it is only part of the reason why we rake lawns.
Leaves Rain on the Parade of Cool-Season Grasses Most lawns in the Northern U.S. are composed of one or more cool-season grasses. "Cool-season" lawn grasses are so called because they are most active during those periods of the year when moderately cool weather predominates. Fall is one of those times. Blessed with sufficient sunlight, nutrients and water, and enjoying temperatures that are neither too cold nor too hot, cool-season grasses such as Kentucky bluegrass revitalize themselves in fall. This is when they must "make hay," strengthening their root systems. But a thick layer of fallen leaves can impede the growth of these grasses. Why? Because they can deprive the grass of one of the key elements I mentioned: sunlight. If not raked up in time, a thick and/or matted layer of fallen leaves casts excessive shade over the grass below.
How Fussy Must I Be About Raking Leaves? When the focus is on lawn health, you do not have to rake up every last fallen leaf. The homeowners whom you see hunting down stray leaves as if they were fugitives from justice are motivated by aesthetics: they are striving for the look of a perfectly manicured lawn. If you do not care about that and just want to keep your grass healthy, rest assured that a few leftover leaves can't hurt your lawn. In fact, if you plan on mowing at least one more time that autumn, the mower blade will simply shred up any remaining leaves.
Speaking of mowing, some people address the leaf-removal issue by running a mulching mower over the lawn in fall. The resulting finely-shredded leaves fall harmlessly between the blades of your grass and serve as a fertilizer for your lawn. As an alternative, you could also use a bag attachment on your mower and empty the contents into your compost bin.
taken from http://landscaping.about.com/od/landscapecolor/f/why_rake_leaves.htm?utm_content=7558556&utm_medium=email&utm_source=cn_nl&utm_campaign=gardening&utm_term
Till next time this is Becky Litterer from Becky's Greenhouse, Dougherty, Iowa