Table of Contents
While certain types of grass choke out weeds once they are established, grass seed on its own will not kill weeds. Zoysia is a popular choice of grass for weed control. It forms a thick turf that won’t allow weeds to grow.
Can I plant grass seed over weeds?
Author: Matt Hagens
Look for a reputable brand of grass seed. It should list “weed seeds 0%” and “other crop seeds 0%”.
Wait until the grass is 3-4 inches tall before mowing for the first time. Avoid weed killers until the grass is established, as well.
Trying to grow grass in a weeded area is a frustrating task that generally provides undesirable results. Weeds are aggressive and invasive plants that choke out grass and flowers. They quickly take over an area and are notoriously hard to get rid of. When you choose to grow grass in an area overrun by weeds, you essentially have to start fresh by establishing new turf.
Cover the soil with the correct grass seed for your location and the amount needed to cover the area. For example, some parts of the San Francisco Bay area work best with warm-season grasses — such as St. Augustine, buffalo or zoysia grass — while other Bay areas thrive with cool-season grasses such as tall fescue and perennial rye. Use your gloved hands to distribute the seeds evenly over areas smaller than 150 square feet. For larger areas, use a seed spreader.
Apply a thin layer – about 1/4 inch – of high-quality topsoil over the grass seed. Applying too thick and the seeds have a hard time germinating. Attach a garden hose sprayer with a mist option to a water hose. Dampen the top 6 inches of the soil with the water hose set on mist. Using a mist of water instead of a stream will prevent the seeds from washing away.
Remove the weeds from the area by either manually pulling them out of the ground or applying weed killer to the area. Hand-pulling weeds is safer for the soil, but removing all the roots can be difficult. Chemical weed killer kills the weeds and their roots, but may damage grass seed and leave pesticide residue in the soil, if you plant the seeds too soon after the herbicide application. If you choose to use weed killer, wait 2 to 3 weeks before planting new grass seed.
Till the top 6 inches of soil with a soil tiller. You can rent or purchase soil tillers at home improvement centers and rental yards. After the tiller turns under the dead weeds and soil, rake the soil with a garden rake to level the area as much as possible. Remove large rocks and break up clumps of soil.
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.
TruGreen offers five different annual plans for your lawn care needs, offering a range of services. Plans come with the TruGreen Healthy Lawn Guarantee®, promising full-program customers that a TruGreen specialist will return to your home as many times necessary to resolve your issues.
Top the seed with top dressing no greater than ¼ inch thick.
Step 8: Lay Down Seed or Sod
If you only have a few pesky weeds punctuating your lawn, you may be able to dig them up by hand—paying careful attention to make sure you get them roots and all. But if your lawn is overrun with weeds, you may need to start from scratch. Here’s our how-to guide on restoring a lawn full of weeds.
To prepare the soil after either method, make sure you till it down to roughly 6 to 8 inches.
Next, it’s time to select the proper weed treatment based on both weed classification and the stage in their life cycle. Pre-emergent herbicides tackle weed issues before they spring up. Post-emergent herbicides target established weeds.
Weeds come in multiple categories, either broadleaf, grass-like, or grassy.