Aeration and Cool Season Grasses
If you have a yard full of cool-season grass, and you’re wondering when to aerate your lawn, early fall is your time! The days are getting shorter and fall is in the air, which makes for a great time to aerate and overseed in many parts of the country. The key is to aerate when grass is in a peak growing season so it can make a speedy recovery, which is early fall for those cool season lawns.
The Difference Between Cool Season and Warm Season Grasses
First you have to define your grass type; what is a cool season versus a warm season lawn? Cool season means that your lawn grass grows best in cooler temperatures which is why you need to core aerate and overseed in the fall.
Examples of cool season grasses include
- Creeping Bentgrass
- Creeping Red Fescue
- Kentucky Blue
- Perennial Ryegrass
- Tall Fescue
Residential lawns, golf courses and parks in the northern half of the U.S. have cool season grasses. Plus, some southern yards, as far south as Georgia, use fescue for those shady spots on their properties.
Meanwhile, warm season grasses get aerated and overseeded in the spring. Examples of warm season grasses include
- Bahia Grass
- Bermuda Grass
- Centipede Grass
- Augustine Grass
- Zoysia Grass
Core Aeration and Overseeding in the Fall
Lawn aeration is done when soil is compacted, and it’s especially important for areas that get a lot of wear and traffic. You actually have only a short window of time to pull plugs while aerating and overseeding your lawn. In northern states, core aeration and overseeding needs to be done well before the first freeze.
The ground is still warm in early September through to mid-October to give seedlings optimal time to germinate. The goal with fall overseeding is for your yard grass to develop deep root systems before winter.
You can use a walk-behind yard aerator that lawn professionals use. However, it isn’t a great investment for homeowners because you do not use it frequently enough to validate such a big expense.
Conversely, you can add an aerating attachment to your lawn tractor to dig deep and pull out plugs of soil, which is an affordable and effective alternative.
Here are seven reasons why you should core aerate and overseed your lawn this fall:
It helps the soil to breathe in and out:
The dirt beneath your feet is a living organism that needs to breathe in oxygen and dispel carbon dioxide. Aerating your soil opens it up so breathing can occur.
It relieves soil compaction:
Foot traffic, lawn mowers as well as clay soil all contribute to soil compaction. Aeration relieves compact soil by pulling plugs of dirt out of the ground.
It reduces water runoff:
A byproduct of aeration relieving soil compaction includes better water absorption with the soil. If you have problems with poor yard drainage, your soil may be too compacted to allow water to percolate through the soil. Stop the ponding by core aerating your yard.
It removes excess thatch:
Thatch is that semi-dry area located between the live turfgrass and the soil line. It consists of dead and living stems, roots and other debris. Some thatch isn’t bad, but when it exceeds a half an inch, it needs to be removed. Core aeration removes thatch as part of the process.
It prepares the soil for overseeding:
Lawn care pros say it’s best to overseed a cool season yard in the fall. Core aeration helps because seed can go deep into the soil forcing the seedlings to develop robust roots systems to survive the winter.
It allows fertilizer, soil amendments (such as lime and gypsum) and top dressing to penetrate deep into the soil:
Before adding soil amendments to your yard, you need to get a soil test to analyze the soil’s pH and missing nutrients. Then, you can add the appropriate amendments to get the soil back to health. An aerated lawn allows fertilizer and soil amendments to absorb into the ground.
- The plugs give your lawn an added boost of microbes and nutrition: When you aerate your yard, you’ll notice small plugs of dirt pulled out of the ground. These plugs are small nutritional pieces that return microbes and other nutrients into the ground the next time it rains or when you water your lawn.
This short list focused on the aeration and overseeding parts of fall lawn care. However, after you plant your new lawn grass, you need to water it regularly so the seedlings can develop before the first freeze.
How to Aerate & Overseed Your Lawn
You know why you should aerate, and also when to aerate for cool-season grass; now you need to know how to aerate your lawn. Here are a few tips for best results:
- Before aerating, the soil needs to be moist enough. Apply an inch of water to your lawn at least one day before to help soften the ground.
- For soil that is only lightly compacted, one good run across the yard may do. However, if you have seriously compacted soil, you may have to go over your lawn multiple times.
- The aerator will pull up soil plugs. Leave them behind on the lawn so that they can decompose and put nutrients back into the ground. You can also break up the dirt plugs by going over them with your lawn mower.
- After you’re finished aerating, sprinkle with fertilizer.
- Now that you’re finished aerating, apply the seed with a lawn spreader
- To finish the job, loosely rake the seeds, then water your lawn regularly so it stays moist for a few weeks after aeration.
Brinly-Hardy Designs Lawn Aerators to Get the Job Done
At Brinly-Hardy, we have aerators that hook up right behind your lawn tractor so you can easily core aerate your lawn this fall. Our yard aerators also differ on how deep the tines or spoons go into the ground to pull out plugs of soil. Here are five of our aerators for you to choose from:
You can find our products online at:
Don’t wait too long. Get a Brinly-Hardy aerator to let your lawn breathe and prepare it for grass seed!