5 Steps to Repairing a Sunken Lawn

If the yard looks like it’s developing craters, there are a few reasons why this happens — buried construction debris, rotted tree stumps, or dirt settling around the septic system. Sometimes a large boulder used to be in the spot, and even though it’s gone now, the depression remains. 

1. Don’t Dig

Before you start digging, Dial 811. A nationwide system is in place to help learn more about how to safely dig in your state. A quick call the local utilities to identify buried lines or request online and work directly with agents in your area. After you’ve had your area flagged, you can break up the ground.

2. Till

Dave Minner a turf specialist with Iowa State University now Emeritus Professor with the Department of Horticulture said to repair a sunken area, get out the tiller to work it up, then fill it with soil.

3. Fill

“You can even use potting soil, or some sand-clay mix, or compost,” Minner said. “If you use straight sand, you’ll have a dry spot in the yard so I wouldn’t recommend that. Compost is a really good thing, you could even mix 60% sand and 40% compost and that’ll grow pretty good grass.”

4. Pack

After all this work, the last thing you want to see is another crater forming in the same spot, so be sure the soil is tamped down well as you’re filling it. For large areas, there is a tool called a “trench packer” that fits on the front of utility machines. It vibrates and shakes and packs.

5. Water

The other way to settle the dirt is simply to wet-pack it with water.

“Pack it as good as you can and leave it bermed up a little higher on it, and then get the hose and just jab the hose into it and really get it good and wet and soaked,” Minner said. “Water is an excellent packer, and it will help that soil settle down and get all those voids and air spaces out.”

Most holes eventually stabilize over time. But if pockets keep forming after several attempts to fill them, call a soil consultant or geologist for an inspection.