Leaf cleanup
Leaf cleanup for Kansas City lawns
Most of the leaves on a lawn belong in it. I chop them into the grass with a mulching mower, and the bagger only comes out for what the lawn cannot take. This is a cleanup visit for leaves. I do not offer mowing.
Leaf cleanup is available in Missouri and Kansas.
What a chopped leaf does for the lawn
Michigan State ran the long test on this, starting in 1991. Oak and maple leaves went into Kentucky bluegrass plots at a hundred pounds of dry leaves per thousand square feet, about ankle deep by the researchers' description, every fall. After six seasons the soil pH had not moved, and neither had phosphorus or potassium. The maple plots rated better for turf quality than the untreated ones on two of four dates in 1997, and color showed no difference at all.
In May 1997, with no herbicide on the plots since August 1995, the untreated plots averaged 33 dandelion flowers, the oak-leaf plots 30 and the maple-leaf plots 4. Most of that gap was on plots that got no fertilizer at all: those untreated plots ran 85 flowers against 9 on maple. On the plots that were fertilized, untreated averaged about 7 and the maple plots under 1, and the oak plots fed in fall were down there with them. On a lawn that gets its November feeding, expect the smaller difference, not the big one. The researchers say they have not worked out whether the maple result is the leaves breaking down faster or something in the leaf itself. The part that does carry over is simpler: leaf pieces sift down and cover the bare ground between plants, and that is where weed seed comes up.
The yards around here are heavy clay and short on organic matter, and Johnson County Extension says organic matter is the fix. Chopped leaves are a small, slow dose of it, added at the surface every fall. Several years into the Michigan State study, the researchers noticed the mulched plots needed less fertilizer for spring green-up. They did not stop needing it. The November feeding still goes down.
When leaves come down here
University of Missouri puts peak fall color in Missouri around the third week of October. Leaf drop follows it, and it runs by species.
- October and NovemberAsh and maple, by MU's timing. These are the easy leaves. Cornell puts maple near the ideal carbon to nitrogen ratio for breaking down, about 30 to 1, so of the two it goes first.
- November and DecemberOak. MU puts oak leaf drop here, and notes that pin, red and white oaks hold many of their dried leaves into late winter and let them go a few at a time. Cornell and the University of California both put oak leaves at about 60 to 1 carbon to nitrogen, with tannins that resist decay, so they break down slowly. That is why I expect an oak lawn to reach the bagging point sooner than a maple lawn.
- Passes go by leaf fall, not grass growthJohnson County Extension says mowing in leaf season is set by the rate the leaves fall rather than by how the grass is growing, each time about an inch covers the turf. On a lawn under a lot of trees that is more than one visit.
- Ahead of the November feedingJohnson County Extension puts the final November fertilizer about the time of the last mowing, which in Kansas City runs mid-November through Thanksgiving. Chop the leaves in before that feeding and the fertilizer lands on grass that can use it. Iowa State says whole leaves left on top block the light the grass needs to store food for winter.
How a leaf visit goes
- Dry leaves, or I waitMU says wet leaves do not chop and leave clumps that smother the turf, and Iowa State wants the layer thin and dry. A wet week moves the visit.
- Deck up, across the leaves in two directionsMU and MSU Extension both say to set the mower high and cross the leaves in a crisscross pattern so the pieces come out confetti size.
- Again, until the grass shows throughIowa State's test is that when you are done, very little leaf debris should be visible, and a layer where little or no grass shows has to be dealt with. If the first pass leaves clumps it gets a second one. Purdue's warning is that trying to mulch six to eight inches at once does not work.
- Then the bagger, for what is leftJohnson County Extension describes the same two steps: the first pass with the bagger off so the leaves are chopped on the turf, the second with it on so the chopped excess is pulled into the bag. Mowing the leaves twice shrinks the bulk, so what goes in the bag is less than what fell, and it leaves with me.
- What it looks like afterDusted brown for a few days. MSU Extension says the pieces settle down through the turf in that time.
What you can do between visits
Leaf season runs for weeks, and I am not there every day of it.
- Do not rake or blow leaves into the street or toward a storm drain. KC Water says they reach streams and rivers untreated, and on the Kansas side Johnson County says nothing but clean rainwater is allowed down a drain.
- If leaves came down in a wet week and sit in a mat, call rather than wait for it to dry. MU says wet, stacked leaves left over late fall and winter will kill the grass under them.
- Tell me which trees stand over the lawn. Maple leaves break down fast and drop early; oaks drop late and break down slowly, and that changes how many visits the yard wants.
- Call when you can no longer see grass through the leaves. Iowa State's line is that a layer where little or no grass is visible has to be managed.
Why the mower goes first and the bagger second
The good a leaf does happens in the lawn, so bagging everything throws it away. The harm starts when the layer is deep enough to shade the grass, which Purdue compares to leaving plywood on the yard, and past an inch or two a pass leaves clumps instead of pieces, which MU says smother the turf. So the mower goes first and takes what the lawn can hold, and the bagger takes what is still on top. The bagged pile is smaller than people expect, because the leaves have been cut twice before any of it goes in a bag.
Questions I get
Does mulching leave a mess?
For a few days, and then MSU Extension says the pieces have sifted down through the turf. If a pass leaves clumps instead of pieces, the leaves were too thick or too wet for that pass, and they get a second pass or the bagger.
Will oak leaves make my soil acidic?
The Michigan State plots had oak leaves mulched into them for six seasons with no change in soil pH, phosphorus or potassium. Illinois Extension says fresh oak leaves are acidic, around 4.5 to 4.7, and break down to neutral or slightly alkaline, and Iowa State says an oak leaf mulch should have little effect on soil pH.
Does it build thatch?
No. MU Extension's 'Don't Bag It' guide says university research shows mulching tree leaves into lawns has no detrimental effect on thatch, Purdue says the same, and Johnson County Extension says chopped leaves do not contribute to thatch. UConn Extension's reading of the research is that chopped leaves add organic matter at the soil surface without building thatch.
What about a thick, wet mat of leaves?
That is the one case where the mower is the wrong first tool. MU says not to mulch wet leaves, or a layer thick enough to leave smothering clumps, and that wet, stacked leaves left over winter kill the grass. Purdue adds snow mold to what grows under a mat. A mat gets picked up, and the thin layer left under it gets chopped in.
I seeded in September. What happens to the leaves on it?
They come off, and sooner than on an established lawn. Johnson County Extension says newly seeded or young grass should have leaves removed as quickly as possible so it can establish, and that getting established before winter is what the new grass needs to survive it. On a September seeding I pick the leaves up rather than chop them in.
Is this a mowing service?
No. The mower is the tool that chops the leaves, so the grass gets cut while I am at it, but the visit is scheduled by how fast the leaves are coming down. Johnson County Extension says the same about leaf season: it runs on the rate of leaf fall. For regular mowing you want a mowing company.
Leaves land on September seed
The seeding window and leaf drop overlap. MU puts seed at August 25 to October 10 and peak fall color around the third week of October, so a lawn seeded in September is still young when the maples let go, and Johnson County Extension says leaves on new grass come off as quickly as possible. If I seeded your lawn, the leaf visit is part of looking after that seed, and on that lawn the leaves get picked up rather than chopped in while the grass is young.
Get a quote for leaf cleanup
Send the address and tell me roughly what trees stand over the lawn. Oaks and maples are different jobs, and a lawn seeded in September changes the method. A written quote comes back.