How should I fill and reseed shallow depressions in my lawn?

Question

I want to level out a lawn that is roughly 4000 square feet. It has many low areas that vary in diameter and depth. Not sure what caused these holes; my guess is that they are from a previous owner gutting out bushes or trees. Some holes have a radius of about 2-3 feet or so and depth of a few inches. I dealt with some holes last summer (the large ones that had a radius of about 4 feet) using topsoil, grass seed and daily watering but I'm thinking it will take too long to fill in everything piecemeal. My plan is probably to till and rake the whole lawn, add some grass seed, and then put down around 14 cubic yards of topsoil. Finally, rake the topsoil over the seed. I will then water it every day for a couple weeks.

Does anyone see any problem with doing the above? What is the most ideal times to do this? Is mid to late April in New Jersey too early (maybe the ground is still frozen)?

Answer 1

I think you'd be better off (less TOTAL work) just filling in the holes gradually. Put 1/4" of soil in the deepest parts. Level it out with a fairly small rake (back of an actual rakehead or short board.) Wait for growth. Add 1/4" of soil, rake/level with a longer board/rakehead. Wait for growth. Add another 1/4", rake/level with an even longer board. Wait for growth....

By the time your board is 16 feet long or so, the lawn is pretty level. You have not churned up any new weed seeds. Each individual round of the work is not terribly difficult. You have grass throughout, with no risk of washing the dirt away in a river of mud if it rains hard while the new grass seed has not established itself.The grass is able to put out new roots and grow in the deep spots, because they are never buried too deep. You never need to fuss too much about watering it because the grass always has good roots, and just has to grow some new ones a little bit higher each time.

If you really want to do lots of work and hurry, hurry hurry, rent a sod cutter, cut all the sod, roll it up and stack it in a shady spot, damped and covered. Fill, level, add new dirt, roll, level, rake, relevel, roll. Put the sod back on. That, you'll need to water carefully if it does not rain for you, until new roots are established. Mow it pretty high for a while to let it make good deep roots.

Answer 2

Rototilling will usually leave a lumpier lawn then before as the soil tends to settle unevenly. It can also bring up new weed seeds. If your lawn is in otherwise good condition it wouldn't be my first choice.

If the lawn is good over the depressions you can cut the sod out, level the dirt and reapply the sod. Otherwise fill and seed the depressions but get a seed that matches your current lawn in color and texture.

"My plan is probably to till and rake the whole lawn, add some grass seed, and then put down around 14 cubic yards of topsoil. Finally, rake the topsoil over the seed. I will then water it every day for a couple weeks"

If you do kill existing lawn and level, do so after spreading the topsoil. 14 yards over 4,000 sq ft will give you about 1-1/8" of top soil. That's too deep for the grass seed. Edit I was really tired yesterday when I wrote this and just realized you don't plan on dumping the entire 14 yards over the seeds.

You're better off reseeding in the fall but now is a good time in NJ too if you're soil temp is above 50 degrees consistently. Depending on were you are you may want to wait a week or so.

Answer 3

Just fill the holes with topsoil. Save yourself a lot of work that will likely disappoint.

Answer 4

I like to fill depressions with composted cow manure mixed with sand. This encourages quick growth to fill in the grass-less spot.