Kathy Brooks

Horticulture Expert,

Hollytree Landscaping

& Garden Decor

in Grove, Oklahoma

In the fall two common tasks that are frequently talked about are aeration and overseeding. For those who have heard friends and neighbors discussing these topics, but didn’t really have a good understanding of just what was involved, here is a basic explanation to help.

Lawn aeration, also known as core aeration is the process of removing small soil plugs or cores from your lawn. The reason we do it is to correct soil compaction on heavily used areas or where we battle heavy clay soils. There are many choices when looking at aerators, everything from hand-type implements that are pushed across the lawn, those that are stepped on, some even attach to your shoes so that you can walk across the lawn and accomplish the task, but most lawn aeration is done mechanically with a core aerator, which has tines mounted to a disk or a drum. A core aerator removes small cores of soil that are usually 1/2 to 3/4 inches in diameter, creating holes ranging from 1 — 6 inches deep, and spaced anywhere from 2 — 6 inches apart. Avoid those aerators that thrust solid spikes into your lawn without removing a core. This process is known as spiking and can further contribute to compaction rather than correcting it. Soil compaction is a problem because it decreases the air spaces in the soil, restricting the amount of air that the root system needs. The roots need oxygen so that they may grow and absorb nutrients and water. Without it, the lawn’s top growth is stunted and eventually deteriorates. Aeration also aides in the removal and breakdown of thatch in the lawn, better supporting the microorganisms in the soil which play a vital role in this process. Overall improvement of the soil structure which supports water and nutrient absorption makes aeration a critical part of lawn care.

Do you need to aerate your lawn? If you know you have heavy thatch buildup or are dealing with a heavy clay soil, chances are the answer is yes. If you have an area in the yard where no amount of fertilizing or watering seems to help the grass to improve, or an area that is constantly walked upon, nothing but good can come from aeration. This is one of those annual tasks that cannot hurt, but can certainly contribute to the health of your soil and lawn.

Overseeding is another commonly discussed fall topic. What is it and why should you overseed? If you have a fescue lawn and wish to thicken it up, now is the time to overseed your lawn. Fescue, depending on the variety can take up to 2 weeks to germinate, so patience is a must. A soil test prior to seeding is advised so that you know if your soil is lacking the necessary nutrients to get the seedlings off to a strong start. Mow the existing lawn to 1 1/2 inches high to allow the seeds to contact the soil, then core aerate the area and apply the seed using a broadcast or drop spreader. Watering twice daily during the initial germination period is critical. Once the seedlings reach a height of 2 inches, reduce the watering to 3 times a week for 20 — 30 minutes at a time. Mow the area when the seedlings are up to about 3 inches tall with the mower set on 2 inches, and, as always, make sure your blades are sharp. Apply a slow release nitrogen fertilizer and water it in well. The fertilizer can be reapplied after 6 weeks, then again 6 weeks later for a total of 3 applications if needed. Weed control has to wait until the lawn is well established so that the seedlings are not damaged by the weed control product.

Take care of aeration and overseeding in the fall so that you have a healthier soil and stronger lawn in the spring. Our area is on the lower edge of the zone where Fescue will grow, which is why it is so important to give the seedlings every advantage possible to develop a strong root system to survive in the heat next summer.