You must wait at least 30 days to seed after applying weed controls. Seeding too soon after applying weed control can prevent your new seedlings from germinating.
Will Grass Fill in After Killing Weeds? A Complete Guide
Having a lush, green lawn free of weeds is the dream for many homeowners. But when pesky weeds invade, it often leads to the use of weed killers to eliminate them. This then leaves unsightly bare patches on the lawn So the big question is, will grass fill those areas back in after weed removal?
The answer is yes, grass can and will spread to fill bare spots left by eliminating weeds. But the extent of the original weed infestation and the overall health of your lawn are key factors in how quickly and successfully it will recover. Follow these tips to ensure your lawn fills back in properly after weed killing:
Evaluate the Initial Weed Situation
If weeds completely overran your lawn, leaving no grass at all, reseeding will be necessary. There’s no healthy grass remaining that can repopulate bare dirt after weed removal. Broadcast spreading seed over dead weeds rarely works since the seeds just sit on top. It’s better to remove dead weeds and till the soil lightly before seeding. This places grass seed in direct contact with soil for proper germination. Using a slice seeder is another great option, as it cuts uniform furrows for seed without disturbing deeper weed seeds.
But in lawns where weeds invaded but plenty of grass still remains, recovery happens quicker after weed killing. The surrounding healthy grass will naturally fill back into any empty spots left behind over time. Spot treating weeds selectively with targeted herbicides is ideal here to avoid harming wanted grass. Just be patient, as even healthy lawns can take weeks or months to fully fill bare patches. Proper mowing, fertilizing, aerating, and irrigation will speed the process.
Prep Your Lawn for Fast Recovery
The better condition your grass is in before weed killing, the quicker it will bounce back afterwards. Here are some tips to prep your lawn for rapid recovery:
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Mow regularly at the proper height – around 3” for cool season grasses. Longer grass shades out weeds.
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Fertilize 4 times per year, using products formulated for each season. Proper nutrients prevent weeds.
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Improve drainage and aerate annually to alleviate soil compaction.
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Water deeply and infrequently to encourage deeper roots.
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Dethatch in spring to remove dead material thatch buildup.
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Overseed thin or bare areas in fall to thicken up grass before winter dormancy.
Take Steps to Rejuvenate Your Lawn
Once weeds are eliminated, actively care for your lawn to accelerate the grass regrowth process:
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Remove any remaining dead weed material by raking carefully.
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Apply a balanced turf fertilizer to nourish the soil and grass plants.
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Water lightly and frequently until new grass is established. Then resume deeper, less frequent watering.
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Reseed any remaining bare spots with a starter fertilizer to jump start growth.
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Allow proper recovery time before mowing or high traffic use of treated areas.
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Monitor and spot treat any additional weed growth with selective herbicides.
Be Patient During the Process
It takes time for grass to spread and fill in bare spots after weed removal. Expect a period of 2-4 weeks for visible progress, and up to 2-3 months for complete infill of larger bare areas. The exact timeline will vary based on:
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Square footage treated
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Overall health of surrounding grass
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Weather conditions
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Time of year
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Supplemental care like fertilizing, watering, etc.
So be patient and consistent with proper follow-up lawn care. Don’t overseed or reseed too soon, as grass needs time to spread at its natural pace. With proper maintenance, your lawn will fill back in beautifully.
Adopt Proactive Weed Prevention
While grass is resilient at filling back into bare spots, the best defense is preventing heavy weed infestations in the first place through proactive lawn care:
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Mow at the ideal cutting height and frequency for your grass type. Never cut more than 1/3 of blade height.
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Water deeply and infrequently to encourage deeper rooting. Avoid frequent, light watering.
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Fertilize based on soil tests using a high quality, slow release fertilizer.
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Improve soil health by aerating and incorporating organic compost annually.
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Adjust pH if needed to optimize nutrient availability.
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Overseed to thicken up turf density in fall.
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Apply pre-emergent herbicides in early spring to prevent summer annual weeds.
Take a total lawn care approach focused on promoting vigorous, dense grass. This minimizes the need for weed killing in the first place. But when weeds do slip through, have confidence that given proper follow up care, grass will fill back into treated areas for a lush, beautiful lawn.
FAQ About Grass Filling In After Weed Removal
Q: How long does it take for grass to fill in bare spots after killing weeds?
A: It typically takes 2-4 weeks to start seeing progress, and up to 2-3 months for total infill of larger bare areas after weed removal. Proper lawn care speeds the process.
Q: Should I reseed after eliminating weeds?
A: Only reseed if weeds totally overtook the lawn with no remaining grass. Otherwise give your existing grass time to spread and fill bare areas, 4-6 weeks typically.
Q: What’s the best way to help grass recover after using weed killers?
A: Regularly water to dilute chemicals and encourage growth, fertilize to nourish grass, and mow at proper heights once grass is established. Avoid excessive traffic on treated areas.
Q: How can I prevent weeds and avoid needing weed killers?
A: Adopt proactive lawn care focused on soil health, proper mowing, fertilizing, aerating, overseeding, and pre-emergent herbicide use. Maintaining dense, vigorous turf minimizes weed issues.
How can we help?
Answer:
You must wait at least 30 days to seed after applying weed controls. Seeding too soon after applying weed control can prevent your new seedlings from germinating.
Below are the seeding wait times for each weed control:
For full post-application instructions, please visit our Weed Control & Prevention product pages.
Killing Weeds and Overseeding Your Lawn
FAQ
Will grass grow after killing weeds?
Glyphosate will kill pretty much everything, including your grass. It kills down to the roots, so no the grass will not come back. If you decide to go that route you will be looking at having to remove the dead matter then prep the soil and replant.
Will grass eventually choke out weeds?
Yes, healthy, thick grass can help to choke out weeds by outcompeting them for resources like sunlight, water, and nutrients.
Will grass eventually fill in bare spots?
Yes, some types of grass will spread and fill in bare spots over time, but not all grasses do this. Grasses like Kentucky bluegrass, bermudagrass, and St. Augustine spread through rhizomes (underground runners) or stolons (above-ground runners), which can help them fill in gaps.
What to do with a lawn after killing weeds?
Roundup® For Lawns is so effective at killing weeds that you may find some bare spots in your lawn after all those pesky weeds die. If you’re looking to liven up your lawn again after using Roundup® For Lawns, turf species listed on the label can be seeded into the treated areas four weeks after application.