The most important part of a lawn isn’t the grass. It’s the soil underneath. If the soil is in bad shape, no amount of fertilizer or pesticide will save it. Late winter and early spring are the right time to get started if your soil needs attention, you need to reseed, or you want to rethink having a lawn at all. Wait until summer and you’ll end up having to use a lot of water trying to save struggling plants from the heat. Here are a few ways to assess and respond to your lawn’s needs:
Topsoil is loose, dark, and full of decomposing organic material. Grass loves it. So, if your yard is a packed clay nightmare, it’s time to put down some topsoil. For healthy grass, the topsoil layer should be about six inches thick.
Knowing the condition of the soil in your yard—pH, electrical conductivity, and how much organic matter, nitrogen and other nutrients are present—will help you determine if the type of grass you’re using is appropriate. USDA Cooperative Extension Service offices will often test your soil for less than $20. All you have to do is collect a sample in a vial or Ziploc bag and send it in for analysis. Be sure the sample you submit says “grass” in the “intended crop” window on the sample’s label. The USDA will give you a few pointers when you contact them.
Even though lawns are technically a type of monoculture, grass is a complex ecosystem, full of plant roots, microbes, and insects. Maintaining that system’s proper function involves keeping the soil loose so that air and water can get in and out. Over time, the soil beneath your lawn becomes compacted, squeezing off nutrients from the grass. Mats of dead root material, called thatch, add to this problem.
It’s up to you to reopen nutrients’ pathways into the lawn ecosystem. The best way to do this is to use a plug aerator. Aerators powered by gasoline engines are common, but they’re difficult to rent in the springtime because demand is so high. If you have a small lawn, don’t want to pollute the air or don’t mind investing a little time, muscle, and sweat, you can buy a manual aerator.
Seed and Water
If your lawn has bare patches, or if the entire lawn just isn’t working, it might be time to reseed. Pick a species of grass that works with your soil type and climate and plant seeds early in the season—basically, as soon as the ground thaws.
To do that, break up the existing topsoil and spread a 1-inch layer of compost over the area to be seeded. Work it into the soil with a tiller or rake, then spread an even coating of pulverized lime on top. Spread the seed by hand, covering the area with an even layer. Gently work the seed into the soil with a leaf rake.
Watering should be done in the morning, but don’t over-water. By avoiding puddles at the surface, you’re encouraging grass roots to grow deeper to find water. When the seeds are freshly planted, it’s a good idea to water in the morning, and again at noon. During the heat of summer, don’t water in the middle of the day. You’ll lose much of it to evaporation.