“How to prep lawn for reseeding” and “preparing lawn for aeration” are some of the most commonly searched topics by homeowners during the end of summer and the beginning of fall. Aeration and seeding are fall lawn care services for most fescue lawns every year that go hand in hand. Fescue seed is needed to repopulate damaged areas of turf, and aeration helps break up natural compaction in the soil system.

Aeration and seeding is a bundled service that is arguably the most important thing you can do for your lawn within a typical year. As a result, knowing how to prep lawn for reseeding will lay the groundwork for a successful aeration and seeding service. There are three simple ways in which a lawn should be prepped for aeration and seeding:

1. The mowing height should be brought down in stages so that it is one to two inches lower than normal by the time of seeding.
2. If receiving core aeration, any underground structures that could be at risk of damage should be flagged.
3. All lawn areas should be watered enough to soften the soil without making it muddy.

In this article, we will explore the step by step recommendations for achieving these preparatory goals. These are the important answers for any questions about how to prep lawn for reseeding, but every yard is different, so be sure to talk to your aeration and seeding provider for specific instructions tailored to your lawn.

For a turf type tall fescue lawn, mowing low is generally a terrible idea. It’s called tall fescue because it likes to be tall, after all! However, the month before aeration and seeding is one time of the year that it is actually a good idea to drop you mower blades one notch at a time. When reducing your mowing height, you always want to do so in stages to avoid stressing out the lawn any more than is necessary.

There are two main reasons that a shorter lawn is better for aeration and seeding. First, turf that is shorter allows for seed as well as any fertilizer like lime to reach the soil surface more uniformly. This contact is important for quick germination and activation. Second, this lower height gives you some growing room once your seed is put down. Proper aftercare for fescue seed dictates that no fewer than three weeks should be spent completely off the lawn. When you wait a month to cut the grass, you can bet it’s going to be tall! Lowering the height now means you’ll have less to catch up to later.

If you have elected to receive a liquid aeration service, feel free to go ahead and skip over the next couple of paragraphs. Fewer tasks under the subjects of “how to prep lawn for reseeding” and “preparing lawn for aeration” is an ancillary benefit to choosing liquid aeration instead of core aeration. However, if you are still receiving a core aeration service, this second part of prep work is arguably the most important.

Typically, core aeration pulls plugs of soil two to five inches deep from the surface of the lawn. As a result, any structures within about six inches of the surface are potentially at risk of being punctured, torn, or tangled by the tines of the core aerator. Because underground structures are obviously impossible to see from the surface, the only way a service provider can avoid these obstacles is for them to be clearly marked with landscaping flags or something similarly visible.

There are myriad types of underground structures that can be an issue for core aeration, but the primary ones that are always a problem relate to in ground irrigation systems. Sprinkler heads and valve boxes always need to be flagged because they sit in lawn areas right at the surface. Sprinkler heads are best located by running your irrigation system one zone at a time and flagging any heads that come up. If a head doesn’t come up, it’s a sign that your system has a preexisting problem.

Another common underground structure is any kind of shallowly buried wire or cable. Electric dog fences, outdoor lighting, and even some satellite or cable lines can be within that six inch problem zone. It’s always best to err on the side of caution and mark anything you know exists that could be a problem, but most areas have public services available that will come out and mark for you exactly where any underground lines run.

Finally, for at least a week or two before aerating and seeding, it is ideal to run sprinklers of any kind in order to soften the yard’s soil. This part of “how to prep lawn for reseeding” is dependent upon the weather each year and with enough rain may not even be necessary. Either way, there are two main reasons that you want a slightly saturated yard for aeration and seeding.

First, the more dry and hard the soil is, the harder it will be for a core aerator to dig as deeply. Yards that haven’t been watered often yield only one inch deep cores as opposed to the three or four inch ones that a watered on can produce. Second, grass seed needs moisture to germinate properly. Soft, damp soil is much easier in which to grow than dry, hard dirt is.

Preparatory watering is a fine balance, which is why it is so important to know how to properly calibrate your irrigation system. Too little water will not fix hard, dry areas of soil, while too much water will result in a muddy mess. Not only does this increase the risk of getting machinery stuck, but it also can lead to great amounts of damage in your lawn from equipment as well as exposure to fungus.

While preparation for aeration and seeding is an important part of the process, the aftercare for your seed once it’s down is vital as well. Be sure to always communicate with your aeration and seeding service provider in case you ever have questions or concerns about the care of your lawn. By the end of the fall, your fescue should be looking Picture Perfect!

Core Aeration & Fescue Seeding FAQ