Renovating your Lawn — Work with What You Have
If your current lawn is not all you want it to be, you may need to renovate — to make it new again. The first step in a renovation is to determine if you have enough of the desired turfgrass present to make renovation more feasible than just starting over from scratch.
If you do not have at least one live plant per square foot of the grass you want, or if you do not have at least 30 percent cover of the grass you want, you should start at the beginning of this publication. If you have patches of the grass you want, the next step is to see why the grass isn’t growing in other places.
The shade is the problem we face most often in many places in the USA. When we start our lawn, we put out sapling oaks, maples, and pines, and we plant bermudagrass. The lawn does well for several years, but then we notice the grass is thinning out and weeds are invading. The problem is the trees have grown enough to shade the bermudagrass. The option is to cut the trees to allow light to penetrate or to shift to a more shade-tolerant grass.
The second major reason turf does not thrive is soil compaction. As we walk on, drive our vehicles across, mow with our riding lawn mowers, and have our children play games on our lawn, the large pores in the soil are destroyed. This slows the rate at which water and air move through the soil and acts as a barrier to root growth. You can solve this problem through aeration or by physically disrupting the compacted layer with a plow. To check for a compacted layer, insert a knife or screwdriver blade 6 inches into the soil. If you feel significant resistance, you probably have a compacted layer.
Lawns thin out for several other reasons
Drought stress thins out the desirable species, and disease pressure causes the lawn to thin. Insects will kill the turf. After the turfgrass is gone, weeds move in. The presence of a great number of weeds is a sign the turfgrass is not thriving.
Before you can make the lawn succeed, you need to find the cause of its decline. Weed growth is a result, not a cause. Killing the weeds will not cause the grass to grow. You must discover if the turf needs nutrients, water, protection from pests, better-drained soil, or whatever it lacks to grow a successful lawn.