If you’re conscientious about maintaining your lawn, it should respond with healthy growth, providing a lush green space that’s both visually beautiful and useful for all kinds of outdoor activities. Grass is a resilient surface covering that repairs itself after both natural stresses and human activity. These disturbances do add up, though, and after a few years you may notice that your lawn is less lush and full than it used to be. If that’s the case, it might be time for reseeding, aeration, or dethatching.
Any time your lawn looks a bit thin, or if you have a few bare patches that need to be filled in, reseeding is the solution.
Before you begin:
Turf experts generally recommend reseeding in the fall (although it can be successful at any time of the year, especially in the spring). Cool-season grasses should usually be planted by mid-September, and warm-season grasses by mid-October. The important thing is to avoid drastic temperature changes and to water regularly yet moderately so the seed has time to absorb moisture and build roots. This will give you a lush, thick lawn in no time.
When the soil under a lawn becomes too compacted, water, air and nutrients have a hard time reaching the roots of the grass. When this happens, aeration is recommended.
If your lawn gets a lot of use and is heavily compacted, you might need to aerate every year or two. Otherwise, every three to five years is usually adequate.
Lawn aerators with hollow tines pull plugs of soil about ½ inch in diameter and 2 to 3 inches deep out of the ground. You can either hire a professional or rent the equipment and aerate your lawn yourself.
To prepare for aeration:
The plugs removed should be no more than about 3 inches apart, and two passes with the aerator are often recommended to ensure complete coverage. The plugs will disintegrate over time, so they can be left on the lawn.
Cool-season grasses are best aerated in late summer or early fall, when there are at least four weeks of strong growing season remaining to ensure that the grass recovers. Warm-season grasses should be aerated in late spring or summer.
Some thatch (the tightly packed layer of organic matter that develops between the grass and the soil surface) is good, because it provides cushioning and helps regulate the soil temperature. But too much can prevent moisture and air from reaching the soil, as well as harboring organisms that make the lawn more susceptible to disease and drought.
Proper fertilization, aeration and mowing can help control thatch, but sometimes it does need to be mechanically removed.
If you think your lawn might have a thatch problem:
You can either hire a professional or rent a vertical mower or power rake. Power rake attachments for rotary lawnmowers are less effective and can damage the grass.
The organic material that is removed by the dethatching equipment can be composted.
Dethatching puts more stress on the grass than aeration does, so it should be done only when needed – and only when the ground is dry. For cool-season grasses, dethatching should be done in late summer or early fall. For warm-season grasses, late spring is ideal.