Fall is the perfect time to think about improving your lawn. The cooler weather makes you feel more like working in your yard and encourages your new grass to vigorously spread its roots! There are a couple of simple things you can do now to make great strides in improving your lawn for next spring – aerating and over-seeding.
What is aerating?
You "aerate" your lawn to reduce the compaction of your soil – something that is especially important in our Carolina clay soils. When your soil is too hard or compacted, it makes it difficult for the roots to grow deep into the soil. Aerating involves running a machine (an aerator!) over your lawn to extract small plugs of ground and leave holes in your soil. These holes allow water, air and nutrients to reach deeper into the soil, encouraging your grass roots to grow deeper as well.
Walk behind core aerator.
The removed soil plug is about the diameter of your finger.
Who should aerate?
Perform this simple test to see if you should aerate your yard:
1. using a flat shovel, cut out a section of your lawn about a foot square and 6" deep
2. pull up this section and look at the side view of the lawn
3. see how deep the roots of your grass are growing:
- if the root zone is only 1" – 2" deep, the yard will benefit from aerating
- if the root zone is already 3" – 4" deep, you don't need to aerate as often
Generally speaking, clay soil needs to be aerated more frequently than other types of soil because it is so prone to compacting.
Caution! You should never aerate within the first year of establishing a new lawn.
When should I aerate?
You should aerate according to the type of grass you have in your yard. For cool season grasses like fescues, you should aerate in the fall. Late August through September are the ideal months, but you can do it through November if the weather cooperates by staying warm enough. (Note: If you are going to over-seed, don't wait until too late in the season because you want to give your new grass time to establish before cold weather snaps. Also, keep in mind that you want your grass established before the leaves start to fall; otherwise when you use your blower to blow away leaves, you can also blow away grass seed!)
If you have warm season grasses, like Bermuda grass, you should aerate during June and July when these grasses experience their most rapid growth.
How do I aerate?
1. Rent a "core aerator". Make sure you request a core aerator – this type will actually pull plugs of soil out of the soil. In clay soils, avoid using the other type of aerator, a "spike aerator"; spike aerators punch holes in the ground, but do not remove the soil plugs and in effect, they compact the clay around the hole even more than before.
Spike aerators – these are often the type of aerators rented to pull behind lawn tractors.
2. Have the utility companies mark your property for buried lines and determine where your invisible fence wire and sprinkler heads are located. Core aerators only penetrate the ground a few inches, but many people have aerated and then discovered their cable televisions or invisible fences no longer work because their wires were closer to the surface than they expected and ended up damaged.
3. Make sure your soil is moist on the day you aerate. You don't want standing water by any means, but if you haven't had rain recently, run a sprinkler on your yard for an hour or so the night before you plan to aerate to allow the water to soak into the soil. If your ground is too hard, the aerator will not be able to penetrate the ground to remove the plugs and you'll end up wasting your time and effort!
4. Run the aerator over your lawn going both one direction and then again perpendicular to that first run (ie, North-South and then East-West). When you examine an area about the size of your spread hand, you should see an average about 5 plugs in that area.
After you've aerated, there are a couple of things you can do to maximize the benefits of aerating. Now that you have the holes in the ground, it makes sense to fill them with something porous to keep the open space available for the rain, air and nutrients to get deeper into the ground. Spreading coarse sand onto the ground will really help with this process. The sand falls into the holes and prevents the soil from just filling in the hole again and compacting the ground all over again.
The most effective way to spread the sand is to toss it out with a shovel and then lightly rake it so it falls into the holes. If you have a large lawn and that seems like a daunting task, it can be spread using several passes of a lawn speader.
Rotary lawn spreader
Top dressing your lawn
If you have poor soil in your lawn, after aerating you may want to top dress it with a good soil such as Blue Max Materials' Lawn Max. Top dressing each year over a few years will help significantly in building the quality of your soil. To top dress, spread a thin layer (one inch or less) of quality soil over the lawn using the back side of a rake – this helps the new soil penetrate down through the grass to the existing soil surface. You don't want to leave it too thick on the surface of the lawn because it will smother out the existing grass.
Overseeding your lawn
The perfect time to over-seed your lawn with cool season grass seed is in the fall, after you've aerated. Choose a grass seed that's appropriate for your growing zone and the type of lawn you already have in place. Spread the seed by scattering it by hand or with a mechanical spreader.
Once the grass seed is down, you'll need to water daily for several weeks to keep the soil moist. You don't want the seed to wash away with a heavy watering, so it's best to water lightly twice a day to just keep it moist.
Watering an established lawn
Once your lawn is established, it's best to water it infrequently and deeply. The recommended guideline is 1" of water one time per week. This watering schedule encourages the grass roots to extend deeper into the soil where there is more moisture available. When you water a little bit every day, you encourage the roots to be lazy – they depend on the surface water and if you miss a few days or your irrigation system breaks, the grass will die quickly because it's not receiving its drink all the time.
To determine if you've given your grass enough water, set your sprinkler to run and put a shallow glass out in the area you're watering. The sprinkler will hit the cup as well and when there is an inch of water in it, you know you're done! (Don't use a tall, narrow glass – the water can bounce off the edges too easily and you won't get an accurate reading).
Following these steps over several years will significantly improve the quality of your lawn and will bring you closer to the beautiful lawn you crave!
For more information, go to www.bluemaxmaterials.com or contact Blue Max Materials at 704-821-2426.