I think what you’re missing is that there’s not a lawn in the forest. There’s leaf mulch and mosses and rocks and decomposing bits of wood, but that lush carpet of grass is only in the clearing and plains, *away *from the trees.
Yes, if you have a small number of trees and a large grassy area for them to blow over, you probably don’t need to rake. But if you have more trees or less lawn, either you rake or you have a patchy lawn (or, best case, you stop trying to grow plants where they don’t want to grow and put in a more native landscape.)
We have a backyard that has a lot of trouble growing grass. Every autumn, it gets aerated / seeded and the grass grows beautifully - until the leaves start to fall and then it gets covered, and all that new grass dies a horrible death.
Especially in one place, where the curved stone wall forms a perfect pocket to gather the leaves.
If we didn’t do multiple cleanups, we’d have nothing back there but solid mud.
This year we’re removing the leaves quite frequently and I’m hoping it’ll help. It is disheartening to have it look untouched, 24 hours after the latest effort.
Maybe a more established lawn, where the leaves weren’t SO concentrated, might tolerate it better (we do not, for example, worry about the front lawn).
We need to look into an alternative for the back yard, for sure.
It’s not a never-ending task of course, the trees only have so many leaves. I just wait until they’ve fallen and grind them up with the mower, I try to go in a circle around trees to blow the chopped up leaves around the bottom of the trees.
I think the worst that can happen from not doing anything about leaves is that they will kill your grass and you’ll just have dirt underneath.
Well, by definition, thatch is not dead grass. According to the lawn care articles I have read, true thatch is grass roots that grow over the soil and block the sun.
Leaves block sunlight, and underneath the leaves it’s cool and damp. Grass doesn’t like cool, wet and no light, so it won’t grow. Leaves also provide hiding and nesting places for vermin, and keeping vermin away from your house is one of the original reasons that lawns became popular.
I have so many trees around my house that if I simply ran a mulching mower over them, my lawn would be covered in a thick bed of mulch by the end of Fall.
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Well, by definition, thatch is not dead grass. According to the lawn care articles I have read, true thatch is grass roots that grow over the soil and block the sun.
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It’s not solely dead grass, but it’s a significant part of it. See Turble’s link which says “Thatch is a tightly intermingled layer of living and dead stems, leaves and roots which accumulates between the layer of actively-growing grass and the soil underneath.”
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Some other perssons have done such studies. We don’t really expect you to do them all.
Leaving short clippings after mowing does not add to thatch development–
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With respect, your link there says “Leaving grass clippings on the lawn, however, does not necessarily cause an increase in thatch buildup.” “Not necessarily” is not the same as “absolutely not” - and all I said earlier was “You can build up thatch with a mulching mower.” I didn’t say you would always do so, I just said it’s possible. I get mattes of dead grass and dead leaf parts which are at least an inch thick and have to be raked once a year.
However, in the very next sentence the link says “Leaving short clippings after mowing does not add to thatch development–soil microorganisms break the clippings down quickly and return a valuable source of balanced nutrients back to the turf.” It also talks at length about how important these microorganisms and fertilizing are. I don’t fertilize, since I try to minimize the disastrous impact lawn care already has on the environment. I’m sure that is part of the problem. Still, raking up the dead thatch once a year should hardly be a hardship.
Leaves can definitely kill lawns up here in the Pacific NW. It might depend on the number and type of trees in your yard, but I could see the difference in my yard compared to the green space directly behind. When I started blowing/mulching leaves in the green space, I started to see grass survive in areas that had only supported ivy and creeping buttercups before.
I don’t know about people who try to blow every day, though. Twice is a week is the most I’ll do, and that only if the weather permits. I do like the look of a clean yard, and I want to do my part to keep the leaves out of a storm drain about two houses downwind of me.
I grew up mowing a lawn with 87 trees to mow around (yes, I counted). Bordering the lawn was the woods. Leaving 4+ inches of leaves on the ground, buried for 5 months under snow, would not make a pleasant scene in the spring. A few years (or less) of this and there wouldn’t be much difference between the woods and the lawn.
Blades of grass, which is what lawn clippings are, are not “dead stems”.
This site has a lot of links to turfgrass reasearch. Here are some links from there, and from Googling.
From Purdue (PDF):
“Clipping removal is generally not recommended on most turfgrass areas. Clippings do not contribute to thatch because they are primarily water and break down quickly.”
From Kansas State (PDF): “Kansas State University research shows clippings do not contribute to thatch.” Also from Kansas State (again, PDF)
From Michigan State: “Thatch is the accumulation of dead and decomposing turf stems, leaves and roots intermixed with live plant roots. Clippings do not contribute to thatch buildup. Clippings decompose quickly and should be returned to the turf.”
From Mississippi State: “The only time clippings should be removed is when the grass is totally covered with clipping after mowing. If you can see the grass blades sticking up through the clippings, you should leave the clippings. The clippings act as a natural fertilizer for the grass plants. Properly mown grass clippings do not contribute to thatch”
From Colorado State: “The idea that clippings left on lawns will cause thatch has been disproven. Thatch is a brown, spongy material consisting of dead grass stems and roots.”
I had a link to a site that said that lawn clippings help prevent thatch, by aiding the decomposition of the grass runners (Stolens and rhyzomes) that cause thatch, but I lost it. I’ll try to track it down after dinner.
Is the dispute herein just over the semantics of what is “thatch?” What else should I call “large mattes of dead cut grass which are not broken down by normal bacterial action and which must be raked once a year in order to allow the grass to thrive and prevent mould from growing underneath?” Give me a noun, folks, and I’ll use it.
I mow my leaves (with a walk-behind mulching lawn mower), and have Truegreen (they used to be Chemlawn, but Truegreen sounds a lot more nature-like, doesn’t it?) put down an application of lime to counteract the leaves’ acidity.
I’ve been doing this for about six years now. Before I started mowing the leaves they’d accumulate to roughly a six-inch depth before I raked them. I have to say that I have one of the better-looking lawns in the neighborhood, so all of that leaf mulch doesn’t seem to be hurting it any.
Thatch Management for Home Lawns (PDF)
"Thatch is the intermingled layer of living and dead grass stems, roots, rhizomes, and stolons that develops between the live green vegetation of your lawn and the soil surface. The thatch layer is composed of plant parts at various stages of decomposition.
Grass clippings are not considered part of thatch because they are 85 percent water and easily decomposed by soil microorganisms."
Now, that is not to say that leaving a thick mat of grass clippings on the lawn does not contribute to the formation of thatch … it can … but those clippings themselves are clearly not defined as thatch.
You may indeed have a thatch problem in your lawn that is being exacerbated by excess clippings. It’s a common problem caused by mowing too infrequently. The general guideline is to never cut off more than 1/3 of the blade of grass, e.g., if you want your lawn to be 2.5 inches, you should mow it when it reaches 3.5 inches. Leaving it until the grass is 4.5 inches high will tend to leave that big layer of clippings. It is sometimes unavoidable, like when it rains 9 days in a row, but mostly it is just that people can’t be bothered to mow that often.
Of course, there could be many other reasons for your specific problem. But semantically, thatch is not dead grass clippings from mowing. It think the noun for that is grass clippings.
I wish there was an icon I could stick in here that indicates: I want to add that of all the people on this board, I would put you at the very top of my list of those most likely to understand the need for using precise terminology. Finding no such icon, I leave you with a
In some cases leaves (if thick enough) can also be a fire hazard if someone throws a cigrette butt out their car window and it should land on your lawn. Also raking leaves is one of the most healthiest exercises for you. You get fresh air, walking,and using muscles that help, plus the bending to pick them up! It also gets you in shape for snow shoveling!
Sorry, I love the snow, and do still shovel our drive even though I am in my 80th year. For those who do not like to shovel I hope the snow will skip their area!
