Aeration and Overseeding
Core aeration is one of the most important things you can have done to your lawn each season. Warm season grasses such as Bermuda and zoysia should be core aerated after spring green-up. Cool season grasses like fescue and bluegrass should be aerated in conjunction with seeding in the fall. Core aeration is important to the health and vigor of your lawn for several reasons: The first is the reduction of soil compaction, and the second is the increase of air, water and nutrients to the roots of your grass.
Compact soil severely reduces the ability of grass roots to expand and take up water and nutrients. The “coring” process created by the aerating machine pulls 1/2 inch diameter cores of soil from your lawn and deposits them on the soil surface.
These cores will break apart within a week or two, and the holes will gradually fill in. Overall, what happens is the top 2 to 2 1/2 inches of soil is loosened up allowing roots to grow outward and deeper.
It is very difficult for water and nutrients to penetrate compact clay soil. If the majority of the water and nutrient material is located close to the surface of the ground, the roots of your grass will also grow close to the surface. This makes the roots susceptible to damage from heat stress, foot traffic, freezes and wind chill.
The ability of your grass to take up and process water and nutrients is directly related to how deep, extensive, and strong the root systems are. The stronger the roots, the healthier, thicker, and greener your lawn will be. Strong healthy roots also help your grass to naturally fight off diseases such as Dollar Spot Fungus. Dollar Spot is most evident in lawns that are stressed and have weak roots, and is often first seen around the edges of the lawn by sidewalks and driveways.
This is due to the increased soil temperatures from the concrete and asphalt which compact the soil and damage roots. Even if your lawn is lush, thick and green, you should still core aerate it every season. Aeration is more useful as a preventative measure than a corrective one.
Overseeding is an overlooked activity in American home lawn care. Homeowners assume, incorrectly, that fertilizer is all that is needed to keep a turf thick and free of weeds. Grass gets tired. It needs to be revitalized every few years.
Overseeding Keeps Lawns Thick And Weed-Free
Overseeding is one of the most important lawn care tasks, yet many homeowners are hesitant to do it. So, you ask, if I fertilize my lawn properly, why do I need to add new seed, especially if my grass looks pretty good right now? The answer is grass is not immortal. Thin grass invites weeds.
Overseeding compensates for that natural slowdown of the turf’s reproduction. There are two major benefits to Overseeding every three or four years. First, you insure your lawn stays thick and dense, or if it has thinned, you will make it thick again. Thick grass has few if any weeds if it is mowed over 3 to 3.5 inches tall. The second benefit is disease resistance.
Early September thru October is the best time to overseed. The key to successful Overseeding is watering, and most of us fall down on the watering job. Once grass seed is spread and moistened from that first watering, it should never be allowed to dry out; it must always be kept moist until you get full germination. That means watering new seed at least twice a day for at least two weeks.
When Should I Mow My Newly Seeded Lawn?
Let the grass grow up to 1/3 higher than its normal height and/or 3.5 to 4 inches total in heights. Remember, the grass roots will typically be very shallow and can be damaged easily.
Cut the grass only when the grass and soil are NOT wet. Mowing when the ground is wet can lead to damaged roots and grass that may prohibit proper germination and growth. Since most new lawns require constant water saturation for their first weeks/months, try to mow during the driest period in between waterings. Try mulching your clippings. Not only will mulching serve as a fertilizer for your new lawn, but it will also provide good ground cover to help keep the soil and roots from drying out.