Why your lawn looks awful, and what you can do about it

How to plant grass seed is a question that eventually crops up for homeowners whose lawns start looking a little thin. In fact, even if your lawn looks perfect, you should still be seeding regularly to keep it in top shape.

"Seeding your lawn can make it less susceptible to pests, disease, and weeds," says Jim Fanning, president of Evergreen Lawn and Pest Control of Orlando, Fla. "When you have strong, healthy grass, weeds have a harder time competing for nutrients and water."

In this latest installment of our Lawn Lover's Guide, we'll fill you in on everything you need to know on how to plant grass seed to keep your lawn looking its best.

How to seed a lawn

First off, odds are you'll want to grab bags of grass seed that are the same strain you already have growing (bring a sample to the nursery if you're not sure). From there, your plans will depend on the problem you're trying to fix. Here are some guidelines for each situation:

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To fill in bare spots (patching): Bare spots can be caused by spilled fertilizer or chemicals, or pets regularly relieving themselves in a certain area. The good news? They are easy to fix.

  1. Prep the area. Rake the bare area to remove any debris (e.g., dead grass and weeds), and loosen the soil to help the tiny seedlings take root once they sprout, says Kevin Shanks, a manager of retail training at Scotts Miracle-Gro.
  2. Apply the seed. Sprinkle the bare spot until it's mostly covered with seed but the ground beneath is still visible. When watered, the mulch in the seeding product will expand to fill the entire area and help keep the seed covered and moist.
  3. Water well. Thoroughly water the newly seeded area until no more water is absorbed. Continue to water daily (or as needed) for at least two weeks, or until the seedlings are 2 inches tall.

To thicken a thin lawn (overseeding): With each passing year, the wear and tear on your lawn can cause it to become thin. Thin lawn repair, sometimes referred to as overseeding, can help return your yard to its original lushness.

  1. Mow low. Set your mower to one of its lowest settings, and cut your grass so that it’s no more than 2 inches tall. Make sure you bag your clippings.
  2. Prep the area. After mowing, rake the lawn to remove any remaining dead grass and debris and loosen the top layer of soil. This will help the grass seedlings take root once they sprout.
  3. Buy or rent a seed spreader. A drop or broadcast seed spreader can be purchased at your local home improvement store for as little as $12 for a handheld unit, or as much as $150 for one with wheels (the larger options are also rentable). A drop spreader, which will drop grass seed directly onto the lawn beneath the spreader, is typically recommended for small lawns. A broadcast spreader, which will spray or broadcast the seed widely, is a better bet for larger lawns.
  4. Apply the product. This is the easy part. Make sure your spreader is set to off, and fill with seed. Set the flow rate — the speed at which the seed will be sent out — according to unit directions. Depending on the model you've purchased, you may be able to then set it to remain on as you walk around your yard. You'll want to cover the whole yard, so it's best to walk the full length of your lawn, then back the other way, in much the same pattern you'd take to mow your lawn.
  5. Water regularly. Keep the soil surface moist by watering daily or as needed for the first two weeks. Resume mowing when the lawn reaches the desired mowing height.
Once you recognize the problem — patchy lawns, thin lawns, etc. — the next step is learning how to seed.

Once you recognize the problem — patchy lawns, thin lawns, etc. — the next step is learning how to seed. (iStock)

To start a new lawn (reseeding): When your lawn is more weeds than grass or is dry and damaged beyond repair, it’s time for a complete do-over.

"A reseeding project lets you start your lawn over with a clean slate," Shanks says.

Here's what you need to do.

  1. Clear the area. Start by killing any remaining poor-looking grass and all weeds with a nonselective herbicide about two weeks before you want to seed your lawn, Shanks suggests. Once everything is dead, rake the area to remove the debris.
  2. Aerate the soil. If your soil is really compact, now is a great time to aerate your lawn, Shanks says. "After aerating, use a rake to level out any uneven areas and loosen the top quarter-inch of soil," he notes. You'll want to follow up with a 1-inch layer of lawn soil, spread evenly across the entire area.
  3. Select your grass seed. You can start from scratch, so choose a grass seed that is right for your location. In the South, warm-season grass types such as Bermuda, zoysia, centipede, and bahia are popular. In the North, lawns do better with cool-season grasses such as Kentucky bluegrass, fine fescue, or perennial ryegrass.
  4. Apply the product. Once your soil is prepped, fill your spreader with seed, adjust the spreader settings according to the label directions, and go for it.
  5. Feed for growth. After spreading the grass seed, apply fertilizer geared to help new grass grow to give seedlings needed nutrients so they can develop a deep root system.
  6. Water daily. Proper watering is a critical step to seeding success. Keep the soil surface moist by watering daily or as needed until the seedlings reach at least 2 inches tall.

How often should you seed a lawn?

Once you've seeded your lawn, you have about five to six years until grass growth will slow down.

"This can lead to those thinner patches, so the ideal time to overseed and fill it in is every three to four years," Fanning says. "You can also reseed in patches if there are thin spots."

If you're growing grass in an area that gets a lot of foot traffic or that has trouble standing up to temperatures, flooding, insects, or disease, you may need to plant grass seed more frequently.

This article originally appeared on Realtor.com as "How to Plant Grass Seed: A Lawn Lover's Guide."