Step 4: Wait It Out
How soon you can plant seed depends on the type of weed treatment you choose. Pre-emergent herbicides will prevent grass seeds from growing just as much as weed seeds, so it would be no good to sow seeds immediately after.
Depending on the type of weed treatment you choose, you may need to wait for up to four weeks. You can ask your local garden center for information about when it’s safe to plant.
Step 5: Rake and Till
Once the weeds—and grass, if applicable—turn brown, it’s time to bust out your rake. Rake up as much of the weeds as you can. Use your tilling fork to pull any extra weeds out and till the soil to prepare it for your amendments and seed.
Step 6: Dethatch and Aerate
Aerating your lawn can help break up thatch, the layer of decomposing organic matter between your lawn’s soil and grass blades. Thatch can be beneficial, since it can make your lawn more resilient and provide insulation from extreme temperatures and changes in soil moisture. But if it gets over a half-inch in thickness, it can cause root damage, including root rot.
Your raking and tilling from the previous step can help with dethatching, but you can also use a dethatching rake if the layer is too excessive.
Aeration improves your grassroots’ access to air, nutrients, and water. Use a spike or core aerator to break up the soil. If you use a core aerator, be sure to make two to three passes in different directions. Allow the plugs of soil you remove to decompose on top of your soil layer rather than remove them.
Step 7: Amend the Soil
Now, you can apply your soil amendment to ready your soil for the grass seed or sod.
Step 8: Lay Down Seed or Sod
You have a choice ahead of you. Do you want to lay down seed or sod? There are pros and cons to each.
- Pros: Less expensive, more variety
- Cons: Takes longer to germinate, can only lay at certain times of year depending on grass type
- Pros: Instant grass, can lay any time of year, requires little maintenance
- Cons: More costly, less variety in grass can mean less healthy lawn overall
To prepare the soil after either method, make sure you till it down to roughly 6 to 8 inches.
First, you need to choose the right type of seed for your lawn. That will depend on the region you live in—one that needs cool-season grasses, warm-season grasses, or a transition zone that allows more flexibility. After you determine which category you need, you can select specific grasses that may have attributes you’re after, like heat- or drought-resistance.
To seed your lawn, lay down approximately 1 inch of topsoil, then use a spreader to apply the seed to the soil.
We recommend using two different types of spreaders. For the majority of the work, you should use a broadcast spreader because they distribute seed evenly, allowing for thorough coverage. But you’ll want to use a drop spreader around the edges of garden beds to make sure you don’t inadvertently drop seed into them.
Always set the spreader to half the recommended drop rate and spread the seed in one direction, then one or two more in different directions to make sure the coverage is nice and even. You don’t want your lawn to have weird patterns or stripes.
Applying the right amount of seed is key. As a general rule of thumb, apply roughly 15 seeds per each square inch, then rake over the seed.
Top the seed with top dressing no greater than ¼ inch thick.
Then, it’s time to add starter fertilizer. Your best bet is to use a starter fertilizer high in phosphorus. However, due to concerns about water pollution, many states prohibit the use of phosphorus in lawn fertilizers. Some states may allow phosphorus in fertilizers for establishing new lawns. If so, you’ll find fertilizers labeled “new lawn” or “starter fertilizer.”