This is a good but seldom-used way to improve poor soil and add organic nutrition by adding a light (quarter-inch) layer of sifted compost or similar, fine organic matter over the lawn surface.
Top-dress early each fall. This is an ideal job to do right after overseeding by covering the seed lightly.
This is another helpful job that can be done occasionally or only when the lawn isn’t performing up to your standard.
Note: Top-dressing can substitute for a late-summer to early-fall fertilizer treatment because of the nutrients supplied by the compost.
Read more on top-dressing
Decaying organic matter and dead surface grassroots make a “spongy” layer between the soil and where the grass blades are emerging. Over-fertilizing, pesticide use, and frequent, shallow irrigation can lead to excess thatch. Letting grass clips on the lawn, as many think, does not. A half-inch or less of this thatch layer is normal, but thicker buildups can inhibit rain penetration and reduce the healthy exchange of oxygen, carbon dioxide, and other gases between the air and soil.
To check your level, dig up a six-inch-square and four to six-inch-deep section of turf and measure how thick the thatch layer is. No need to routinely dethatch, as some people do. Dethatch only if you’re seeing poor lawn growth, and you find more than an inch of thatch buildup.
Late August through October is ideal for using a dethatching machine or stiff rake to rip out excess thatch. Compost it or use it as mulch (if the lawn hasn’t been treated with herbicides). Then monitor every year or two and repeat if unacceptable levels build up again.
It is better to correct the underlying causes of excess thatch than to remove it as it keeps building up.
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This is a way to correct hard, compacted soil that’s making it tough for grassroots to spread and thrive. It involves using a machine with a rolling, spiked drum to remove cores of soil and deposit them on the surface.
Consider aerating if the lawn is thinning and weeds are becoming a problem, especially in conjunction with over-seeding and then top-dressing.
Do it every early fall or two and follow up by spreading new grass seed, which will germinate in the openings and encourage a thick, dense lawn.
Read more on aerating the lawn
Lime is a mineral that makes lawn soil more alkaline in cases where the soil is too acidic. Lawns perform best in near-neutral conditions (a pH of around 7).
Lime is not a regular need, though, as many believe. You may never need to apply lime if the soil in your area isn’t overly acidic.
A soil pH test is the best way to tell if you need a lime treatment.
If your soil test indicates you need lime, use granular (not powdered or pulverized) lime and apply it in the fall before the ground freezes. Early spring is another good time.
Read more on liming the lawn
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