If patches of grass in your lawn have been killed by Roundup, there’s no way to revive the brown grass. Instead, return your lawn to its pre-Roundup appearance by removing the dead grass and the top inch (2.5 cm) of soil with a shovel. Then prepare the soil for new grass by loosening the soil and adding new topsoil if necessary. Next, either lay new sod or spread grass seed on the bare area. Water the new sod or seed so that it takes hold. Moving forward, use a selective herbicide to kill weeds growing in your lawn without harming your grass.
Will Grass Grow Back After it is Sprayed with Roundup?
Roundup kills grass and all other plants to the root. So, the brown patch of grass where you sprayed Roundup on your lawn will not green up or grow back on its own. Unlike grass that is brown during winter dormancy, grass that is sprayed with Roundup will not return to life. Only removing and replacing the grass will fix the dead spot.
Can You Reverse the Effects of Roundup on Grass?
There is no way to reverse the effects of Roundup exposure on grass or other plants. Even if you attempt to wash the Roundup off the grass immediately after spraying, it may not work. Grass that has already turned brown after Roundup exposure is completely dead. Just like any other dead organism, dead grass plants can’t be brought back to life.
5 Tips to Repair Grass Killed by Roundup
Roundup is a powerful weed and grass killer, but you can still return your entire lawn to a green color if some of your grass was killed by Roundup. Here’s how to encourage complete lawn recovery if you accidentally killed some grass while spraying Roundup on unwanted weeds.
Remove the Dead Grass
There are several effective methods for removing dead grass killed by Roundup. For small dead patches, begin by digging up and discarding the dead grass that was sprayed with Roundup. First, use a shovel to cut an outline around the dead spot. The line around the dead patch should be 1–2 inches deep (2.5–5 cm). This will be deep enough to cut through most of the grass stems and root material.
- Use this serrated shovel to cut a line 1–2 inches deep (2.5–5 cm) around the perimeter of the dead grass area.
- Tilt the shovel so that the head is almost parallel to the ground, then work it under the dead grass.
- Pry up the dead grass along with 1–2 inches of topsoil.
- Throw out the grass or add it to a compost pile.
Once you have outlined the dead spot, push the shovel under the dead portion of grass and pry it up. Again, the shovel only needs to go 1–2 inches (2.5–5 cm) below the soil surface. Think of this job like cutting a piece of sod out of your yard. For large dead spots, it helps to cut the dead grass into sections and remove them piece by piece. Once it’s removed, you can discard the dead grass or compost it.
Prepare the Soil
Once you’ve gotten rid of the dead grass, prepare the bare soil for new sod or grass seed. Start by using your shovel to loosen and turn the top 6 inches (15 cm) of soil. This helps young grass take root faster. Then, mix some new compost or topsoil into the dirt. This will provide a growth boost for the new grass you’re about to plant.
- Use a shovel to loosen the top 6 inches (15 cm) of soil in the areas where you removed the grass.
- Add topsoil and/or compost to the bare area to make sure your yard remains level.
- If you are planning to lay sod in bare areas, add topsoil until the bare spot is 1 inch (2.5 cm) lower than the rest of the yard.
- If you are going to seed the bare spots, add soil until the bare spots are just below level with the yard.
- Walk on the bare spots to lightly compact the soil—add more soil if it seems too low.
How much compost and topsoil you add to the bare area depends on whether you are laying sod or spreading grass seed on the bare areas of your lawn. If you are laying sod, add just enough soil so that the bare spot is still 1 inch (2.5 cm) lower than the surrounding grass. If you plan to spread grass seed in the bare area, add compost and soil until the bare area is almost level with your yard.
Lay New Sod
If you are replacing the dead grass in your lawn with sod, determine the square footage of sod you need to cover the bare areas. Then, purchase 25% more sod than you need. This will allow you to precisely cut sod to fit. Once you have your sod, lay it in place and trim the pieces so they completely fill the bare area. Then, follow our keys for new sod success so that your sod takes root fast.
- Measure the bare areas of your lawn and determine the square footage of all the bare spots combined.
- Multiply the total square footage of bare spots by 1.25 and purchase an amount of sod that matches this square footage.
- Ordering extra sod allows you to trim pieces to fit.
- Lay your sod in place.
- Use this sod knife to cut sod to completely fit the bare area.
- Using sod instead of seed will help your lawn recover faster, and help keep weeds out.
Whether or not you lay sod or seed depends on the type of grass in your lawn, as well as your preference. Some grasses—such as St. Augustine—must be grown from sod since seeding does not work. Most other grasses can be grown from sod or seed. Your lawn will look better faster with sod, but using grass seed is typically cheaper.
Re-Seed The Bare Areas
Once your soil is prepared, purchase your grass seed and start reseeding the prepared soil. Spread seed on the soil by hand until the seeds are as densely packed as the seeds on a sesame seed bagel. Then, water the seeds immediately after planting. It is essential to follow a schedule for watering new grass seed so it sprouts and grows to maturity.
- Purchase grass seed that is the same type of grass that is growing in your yard.
- Using your hand, sprinkle grass seed until there are about 16 seeds per square inch.
- Water the soil immediately after seeding.
- Continue to water frequently until the grass seed sprouts and establishes itself.
- Do not mix grass seed of a different variety with your existing grass—the new grass will stand out.
When seeding your lawn, purchase grass seed that matches the grass variety in your yard. Do not mix grass types. Different grasses are different in color and texture, which results in a messy look. To restore your lawn to the same appearance it had before it was damaged by Roundup, make sure you know your grass type so you can buy matching seed.
Use Lawn-Safe Weed Killer in the Future
When tackling weeds that crop in your lawn going forward, make sure you choose a selective herbicide. Selective herbicides are designed to kill broadleaf weeds (non-grassy plants) but won’t harm grass. In comparison, Roundup is a non-selective herbicide. This means Roundup kills all plants, including grasses. There are many selective herbicides to choose from. Speak to a professional at your lawn and garden center to find a herbicide that is safe for your lawn.
- Never spray Roundup on weeds growing in your lawn—this will produce more dead grass spots.
- Roundup is a non-selective herbicide, which means it attacks all plants and grasses.
- Speak to an expert at your local garden center to find a selective herbicide that will attack weeds in grass but won’t harm your lawn.
Do not spray any weeds in your lawn with Roundup in the future. Lawn grasses are quickly killed by Roundup. Instead, use Roundup to kill weeds growing in cracks in sidewalks and driveways.
When Can You Reseed After Using Roundup?
After you spray standard Roundup on your lawn, you can reseed after 3 days. However, Roundup has a wide range of products. Some are designed to kill weeds and plants in soil for up to 12 months. So, you may have to wait longer to spray for weeds if you used one of these weed killer sprays.
How Do You Fix Roundup-Damaged Grass?
Repairing brown spots in your lawn caused by Roundup is simple when you know the right steps. Roundup kills grass permanently, so you’ll need to use these tips to bring green grass back to those dead zones:
- Using a shovel, remove the dead grass along with the top 1–2 inches (2.5–5 cm) of topsoil.
- Loosen the topsoil and add compost to boost new grass growth.
- Lay sod and trim it to fit the bare areas of your lawn.
- If you do not wish to lay sod, spread grass seed on the bare areas instead.
- Use only grass-safe selective herbicides to kill weeds in your lawn, once it is repaired.
This system will revive your lawn. Roundup products can wreak havoc on grass, but your lawn can bounce back with a little help from you.