Lawn overseeding

My plan is to spread seed and then top it with 1" of Leafgro. Smart or not?

How about 1" Leafgro first, then seed?

Will the seed germinate if it is only (or primarily) in contact with Leafgro?

How about topsoil then. Seed first, covered with 1" topsoil? Or topsoil first, then seed?

Do I really need to roll it? 'cause that’d be a &$!@#.

Many thanks.

Are you putting seeds into your existing turf?

Yes, onto existing turf. But it (the existing turf) is very sparse and thin.

How compacted is the soil? If not too bad, just lightly rake it to loosen it up a bit, then do the overseeding with the existing soil. I like the idea of throwing down some of the leafgro compost to cover it.

If the soil’s compacted, in the really bare areas, put down a thin layer of soil/compost mix first. You could even get away with just a thin layer of compost. (You don’t necessarily need more soil, but I like to mix my compost with a bit of soil.) Put the seed on top of the compost and/or soil. Cover with straw to keep it covered from the elements and birds.

The key is to not put down too much seed. Maybe 6lbs/1000 sq ft. More isn’t necessarily better, and can actually hurt. Too many seedlings competing for sunlight, water and nutrients won’t produce the results you’re looking for.

Do it again in the fall. Early fall is the best time to overseed, when the seedlings aren’t competing for space with germinating weeds.

Your comment about rolling leads me to figure you don’t really want to get involved with spreading topsoil.

Planting grass seed at the correct depth is very important – read the label on the seed you buy and follow the instructions. Typically, grass seed should be covered by 1/8 to ¼ inch.

If you are just spreading compost on top and not tilling it into the soil an inch of compost is too much; ¼ inch is more like it – so if you buy seed that should be planted ¼ inch deep and cover it with ¼ inch of Leafgro that should work well.

Running a roller over it will help insure the seed germinates; grass seed needs to be in firm contact with the soil to sprout. It doesn’t have to be a heavy roller; you only want to compact the soil enough to ensure the seed is making good contact. Another trick to get good soil contact is to “drag” the lawn after overseeding; drag a piece of chainlink fence, old piece of carpet, an old board, a piece of chain, anything that will shake the seeds that are clinging to existing grass blades down to the soil – then roll it.

So – spread the seed, drag the lawn, spread ¼ inch of Leafgro. That should do fine, and it will be even better to then run a roller over it because more of the seed will successfully germinate. Due to the rich organic nature of the compost I wouldn’t add any fertilizer at the time of seeding.

Following the watering instructions on the seed package will also help a lot if you want a quick start, or you can let nature take its course and many of the seeds that are not eaten by birds will eventually sprout. Spreading a layer of straw on top will help prevent loss to birds and it helps the grass seeds germinate; grass seeds prefer to germinate in the dark – weed seeds like dandelions prefer to germinate in the light. The straw disappears over the course of a few weeks and adds a bit of organic matter to the soil.

Watch the forsythia bushes in your area. Plant your grass seed when the forsythias are dropping their flowers.

You can plant grass seed any time but it is correct that early fall is the best time, right around Labor Day for most temperate areas … so do it again then.

This should be done in Fall.

Doing so now can encourage weed germination and sidetrack your overall grass-over-weeds campaign.

If you look around, there are pre-emergents that can be used with certain types of grass seed, but getting seed going now is a compromise.


No sense letting the weeds grow all summer without competition. Plant your grass when the yellow flowers are dropping (that’s the indication that the soil is staying warm enough overnight for the seeds to do well), then do it again in the fall.

Spot treat weeds with something like Weed-B-Gon or use one of the hose-end sprayers if you have a really bad infestation. Best thing I’ve found for dandelions is the Fiskars Uproot Weed Remover.

Don’t know how thin your lawn is. Seeding can be done here - Chicago area - spring or fall. In fact, my preference is spring, when I’ve personally had better success. There are windows in the spring and fall that you should try to hit. Check with any garden center (or on-line I expect) to figure out yours. I’d probably aim at doing it between mid-April and mid-May. In the fall, probably early October.

My approach for filling in patches is to rake the patch hard with a dirt (not leaf) rake, so that you clear out any thatch and make furrows in the dirt. If the soil works nicely enough ad I don’t care to put in the effort, I may just rake some seed into that soil. But optimally, I would spread <1" of topsoil on the area. Then spread seed onto the topsoil, and work it in by raking lightly such that only 1/4-1/3 of the seed is visible. Some folk advise using the back of the rake.

Buy good quality grass seed for the conditions you have (sun, part shade, heavy traffic…) Make sure it is from this year, and check the contents. I suggest buying in bulk from a reputable garden center, rather than a prepackaged bag/box. It might seem more expensive per pound, but you can buy exactly the amount you want, and different types if you have sunny and shady areas.

IME, the most important step is to water it regularly. The seed needs to be moist to germinate, and the young grass needs to be wet regularly to survive. Before germination, I’ll often water morning and evening - not a lot, just keeping the soil moist. After germination a single hot/dry day can be enough to kill young grass. So for the first couple of weeks make sure that you water it at least once a day if it doesn’t rain. By the time you give it its first mow, it needs far less water.

Also, be very careful of any weedkillers or fertilizers you put down before or while seeding. Definitely don’t put down a pre-emergent weedkiller.

I don’t know what Leafgro is, but I often get a kick out of seeing folk use that bluegreen mulch stuff. Way too often, they neglect to water it, and the stuff hardens into something resembling paper-mache.

I’ve never overseeded an entire lawn. If I were going to do so, I’d do what I’ve seen golf courses do, and mix seed with sand/dirt, and spread a thin layer of that mixture. Any existing grass can grow through the thin layer of soil, but the soil will protect the seed. Of course, golf courses have equipment, materials, and labor that exceed what is likely available to a homeowner.