The best time to aerate your lawn is based on 3 conditions:
- Type of grass in your lawn
- Weather conditions in your area
- Amount of moisture your lawn has received
Aeration can take place at any time of the year, but the best time is usually in the spring/early summer or fall.
The general recommendation is to core aerate when there is the most root growth. For warm-season grasses: Bermuda, St. Augustine, Centipede, Zoysia, it is in May and June when these grasses are coming out of dormancy. Cool-season grasses: bluegrass, ryegrass and the fescues, receive the most benefits when the lawn is aerated in the fall.
What would happen if you aerated a warm-season grass in the fall?
In most cases, nothing bad. The roots of the turfgrass will probably not grow any faster. But there is still the benefit of helping to reduce compaction. When a lawn is aerated, a certain amount of soil is lifted from the lawn and left back on the lawn.
As these cores are broken apart by mowing or melt into the lawn through rain fall or irrigation, the soil will intermingle with the current thatch layer and start feeding on it to naturally break it down. The only concern would be if abnormally cold temperatures were to occur and the ground were to freeze. This may cause some roots to die that are close to the edge of the core holes.
Fall may be the best time to aerate a cool-season lawn, but in some cases, aeration in spring and fall may also be recommended. If the thatch layer has been built up above a half of an inch over a period of time, spring and fall aeration may be the best choice. Many people like to seed after aeration, but we don’t recommend seeding a lawn in the spring, since we cannot apply a crabgrass preventer and the lawn will require more watering than it will in the fall.
The most important condition that can affect the quality of aerating a lawn is the amount of moisture that is in the soil. The lawn has to be moist for the tines to penetrate into the ground. Be sure to either wait until after a good rain fall or provide about a half inch of water to the lawn before trying to aerate it.
If you have not scheduled your lawn for a fall core aeration, especially if you are in the cool-season turf areas, contact your local Spring-Green office. It is one of the best things you can do to help ensure you have a healthy lawn.