Lawn Aeration with Over-Seeding
The single most important thing you can do for your lawn
At Green Giant, the blades of grass are not the first thing we think of when we develop a plan to create a beautiful lawn. Our first thoughts are of the soil and the root system. With this approach, annual Aeration and Over-Seeding always comes to mind. There is no other process that provides as many benefits to your turf grass as Aerating and Over-Seeding.
All lawns benefit from annual soil aeration with over-seeding – especially lawns growing with poor quality topsoil or that have a lot of activity (foot traffic) especially benefit from aeration each year. Over-Seeding is simply spreading high quality grass seed at the time of Aeration which is a great way to thicken up a thin lawn, fill in dog spots or other dead areas of grass.
At Green Giant, we provide core aeration, a process that uses hollow tines to remove thousands of soil ‘cores’ or ‘plugs’ of soil. These plugs are ¾ inches in diameter and can go as deep as 5 inches. Equipment having solid tines or spikes should not be mistaken for core aeration equipment.
Benefits of Green Giant’s Lawn Aeration with Over-Seeding:
A Thicker, More Lush Lawn
Simply spreading grass seed over a lawn will not provide good results. The grass seed needs a ‘seed-bed’. Aeration provides that seed-bed in the form of the aeration holes.
See the progression pictures below to see what Green Giant’s aeration and over-seeding can do!
Reduced Compaction of Soil
Core Aeration is the only way to alleviate soil compaction in a lawn. Compacted soil can greatly reduce water and air circulation to the root zone (which healthy grass needs). Compacted soil also limits the ability of fertilizer to get down to the root system where it is most beneficial.
Another problem with compacted soil is root growth. When you think about it, compacted soil is dense with few or no air spaces. It also holds very little water and is much less of a ‘living environment’ than aerated soil. All of these characteristics make it difficult for the plant’s roots to grow through the soil and spread.
The better the plant does below the soil (root system), the better the plant will do above the soil (grass blades)
Management of the thatch layer in a lawn
What is the thatch layer in a lawn?
Thatch is a layer of dead and living, intermingled, grass roots, shoots and stems that builds up between the soil and the grass blades in a lawn. When the thatch layer gets thicker than ½ inch a lawn will most likely develop problems.
What causes a thatch layer to build up?
The parts of a grass plant that make up the thatch layer do not decay quickly. Therefore, it is common for a lawn to produce roots, stems and shoots faster than they decompose, resulting in a build-up of the thatch layer. That is where aeration comes in.
When the aerator pulls out plugs of soil, it punches through the thatch layer and drops the plugs on the lawn. It is interesting that, thatch in the thatch layer is harmful to the turf but, when the plug of soil and thatch is deposited on the lawn, it provided beneficial organic matter to the soil. Rain and mowing will quickly break down the plugs.
Why is Thatch in a Lawn Bad?
If the thatch layer is not managed, it will create a barrier that will cut-off air and water circulation to the roots of the grass plants. It also inhibits the fertilizer from getting down into the root system.
When a thatch layer gets too thick (over ½”) the grass’s roots will begin to grow in the thatch layer instead of the soil. Grass can grow with its roots in the thatch as long as it is wet outside however, when the weather changes and things dry out, the grass can die.
Any Other Benefits of Aeration?
Since aeration improves the root system of your lawn, the grass will have more tolerance heat and drought.
Lawn aeration will also improve resiliency and cushioning for your feet. This is an important benefit to sports field managers when players will be running and falling on the turf.
Aeration Progress Photos
A Lawn’s Improvement after Aeration with Over-Seeding
While Aeration with Over-Seeding is primarily used to fill in thin grass areas or small bare patches in a yard, it can also re-establish completely dead sections of grass. The pictures below show how Aeration with Over-Seeding can fully re-establish the lawn and the time the process takes. A four-foot diameter baby pool was in the lawn all summer and caused this dead patch of grass.
The process of building the density of turf takes time with any method. During the Aeration, small “plugs” of soil are pulled out of the lawn. Grass Seed is then spread over the lawn and the majority of the seed will germinate in the aeration holes. Aeration with over-seeding creates minimal disturbance of the soil and is much less messy than rototilling which leaves completely bare soil which gets muddy and can wash away in rain.
This picture (above) was taken the day the aeration and over-seeding was done. You can see the ¾” diameter holes and plugs of soil removed by the aerator (especially if you zoom in). The majority of the grass growth will occur in the aeration holes which provide a mini-seedbed. These holes do not dry out as fast as the surface and the seed doesn’t get eaten by birds or washed away in the rain.
After 14 days (October 30)
The pic on the right is a close-up showing seedlings coming out of an aeration hole.
The good news: There is progress! The bad news: It’s really hard to see. Green grass seedlings are beginning to pop up in the aeration holes (picture on the right). You have to get really close to see this. The blades are very thin, somewhere between the thickness of a strand of hair and a thread. Looking closely, seedlings can be seen growing out of every aeration hole. The seeded areas have been watered as described in Green Giant’s Success With Your Seeding handout.
Given it is October 30, the new grass may go dormant and additional growth may have to wait until spring. But this is OK. We have established the seedlings and, in the spring, as soon as the soil temperatures are warm enough, the young grass will start growing again.
After 6 weeks (December 2)
Ok, this was a surprise. With more mild temperatures, the grass has continued to fill in. Not that the patch looks great, but when comparing to the earlier pictures, you can really see some progress. This is a huge head start over spring seeding!
If we had waited until spring to seed, this would still be a bare patch.
A little more progress…
Yes, this is the same spot as you saw in the first picture! For the last 4-5 weeks we have had good, spring growing conditions. It does take some time but, with some care, Aeration with Over-Seeding works. At this point, the grass has completely filled in and you cannot see a difference from the rest of the lawn.
Over-Seeding at the time of Aeration is a great way to thicken up a thin lawn or introduce better grass types to a lawn. Simply spreading grass seed over a lawn will give very poor results. By aerating first, the soil is cultivated, greatly improving the results. The majority of the new grass will grow in the aeration holes. “Tufts” of new grass will grow out of the holes and then “tiller-out” and thicken up the lawn.