In cold-winter climates, freezing and thawing causes soil to heave and become bumpy and uneven. Even earthworms can cause your lawn to become uneven, by leaving castings on soil surface. If you have a high or low spot in your lawn that raises havoc with your mower, here’s how to fix it:
With a spade outline the uneven area by pushing the spade in a few inches around the perimeter.
If it’s a large area, cut across the middle with the spade so that you create 18- to 24-inch wide strips of sod. Then push the spade about 2 inches underneath the sod and gently pry it up so that the roots separate from the soil.
Roll up the sod and keep it moist.
If it’s hot, put the sod in a wheelbarrow and move it to a shady spot.
Turn the soil with the spade and add or remove enough soil to bring the area to the proper level.
Don’t forget to consider the thickness of the sod. Water the area to settle the soil.
Replace the sod.
Unroll the sod in the same order in which it was removed. Because the bottom of the sod probably won’t be smooth, shave off a little or remove some soil so that it sets evenly.
Water the leveled area just as you would newly planted sod.
You may need to water more than once a day in hot weather.
If you have a small low spot, you can often raise it simply by gradually spreading good soil (potting soil works well) over the area, no more than an inch at a time. Eventually the grass grows through the soil, and the area will be higher.
Another way to level your lawn is with a water-filled roller during the spring months. The soil should be moist, but not saturated. Fill the roller about a third full of water and go back and forth over the lawn. If the surface hasn’t evened out, add a little more water and repeat the process until you get a level surface. However, be careful that you don’t overdo it, or you’ll compact the soil and cause other problems.