Although clay soil often gets a bad rap due to its high water retention and dense texture, it can be fertile ground for a healthy lawn. Clay soil usually requires a bit of TLC, though, before it can support an established lawn. For best results, take soil samples to your local university extension for a thorough analysis of your soil texture and nutrient levels.
About Clay Soils
Soils are commonly classified by their texture, which refers to the size and amount of space between soil particles. Clay soils have fine particles that tend to be very close together. When the soil is wet, the particles stick together, forming a claylike substance. Although it can take some time for water to penetrate the surface, clay soils retain water well and are often quite fertile when improved with soil amendments and good gardening practices.
Although some types of grass can survive in clay soil conditions, others may struggle. This is because clay soils can become waterlogged easily and may not provide enough oxygen to grass roots. Waterlogged conditions can cause increased susceptibility to pests and diseases such as root rot. Clay soils also have a tendency to become compacted, which occurs when the top layer of soil becomes compressed so tightly that air and water cannot reach roots below the surface. In severe cases, compacted lawns may require complete renovation, reports the Clemson Cooperative Extension.
Amending Your Soil
If you have high clay content throughout your lawn, apply soil amendments to establish a successful lawn. According to the Ohio State University Extension, organic matter like compost or peat can be added to the soil and incorporated into the top 3 or 4 inches of the soil. Organic matter increases the amount of space between soil particles, giving grass roots plenty of access to oxygen and water.
Other Control Methods
Aerification, also known as core aeration, may be required for compacted lawns. For small areas, you can aerate your lawn by digging holes in the lawn with a spading fork. This will increase the oxygen available to roots and reduce water runoff. For larger areas, you may need to rent a power-driven core aerator or aerifier from your local home improvement or garden centre. If you haven't planted your lawn yet, you may be able to prevent problems by choosing a grass species that tolerates clay conditions, like Bermuda or zoysia.