The best time to reseed a lawn depends on the grass type. Cool-season grasses should be reseeded during late summer to early fall, while warm-season grasses are best seeded in late spring to early summer.
However, you will want to start the process of preparing your lawn – mainly killing off the grass and weeds – much earlier. Weed killers take time to work their magic, and you need a blank canvas to reseed.
Best time to reseed cool-season grass
Late summer to early fall is the best time to reseed cool-season grass. Cool-season grasses include the following:
You’ll want to plant your cool-season grass seeds when the soil is around 50 to 60 degrees Fahrenheit (60 to 75 degrees in air temperatures). The exact time will depend on the average temperatures in your area:
- Homeowners in northern states such as Massachusetts and Washington can plant grass as early as late August, but they’ll need to get their seeds in the ground by early October.
- Transition zone homeowners like those in Kentucky and Oklahoma will generally plant their cool-season grasses later than those living in more northern states. September to late October is generally a good time to reseed.
Note: Plant your cool-season grass at least 45 days before the estimated date of the first fall frost.
There are a few reasons why these times of the year are good for reseeding cool-season grass:
- Perfect temperatures. These soil temperatures are the best for cool-season grass germination. The air temperatures are also perfect as they will generally be cooler; cool-season grasses are more cold-tolerant than they are heat-tolerant.
- Less weed pressure. There tend to be fewer winter annual weeds than summer annual ones, so your grass has less competition. Perennial weeds also will start storing energy in preparation for winter, so weed killers will be more effective against them.
- Some rainfall. Homeowners will need to keep their grass seeds moist as they sprout, so having some rain throughout the season is welcome. Typically, fall rains are less heavy than spring showers, so your seeds won’t be displaced. Drier conditions also mean a lower risk for lawn disease.
Best time to reseed warm-season grass
The best time to reseed warm-season grass is late spring to early summer. Warm-season grasses include the following:
Warm-season grasses germinate best when the soil temperature is 65 to 75 degrees Fahrenheit (around 80 degrees in air temperatures). Like with cool-season grass reseeding, the exact time will depend on the average temperatures in your area:
- Homeowners in the transition zone like Tennessee and Nevada with warm-season grass will plant their grass seeds earlier than those living further south. You may need to wait until mid-April or May before planting your grass.
- Those living in southern states like Florida and Louisiana can reseed their lawns earlier. You might be able to seed in March (or even earlier if you live somewhere with consistent temperatures year-round) up until the fall months.
Note: Plant your warm-season grass no later than 90 days before the estimated date of the first frost.
Here’s why this time of year is best for reseeding warm-season grass:
- Opportunity to establish. Your warm-season grass has an entire season to grow a strong root system before the hottest summer days and the first fall frost.
- Warm but not scorching hot. Late spring and early summer have warm temperatures that promote warm-season grass seed germination. Warm-season grasses are also more resistant to heat than they are to cold temperatures.
- Spring showers. Spring rain helps keep your seeds moist, meaning you’ll need to use your sprinklers less.
When to start preparing your lawn for reseeding
While the actual planting of the grass seed is accomplished in the time windows we mentioned above, you’ll want to start preparing your lawn much earlier. This is because it takes time for your grass and weeds to die off.
How early you should prepare your lawn for reseeding will depend on what method you want to use to kill all vegetation.
Herbicides. If you’ll be using non-selective herbicides to kill off your lawn, start applying weed killer at least a month before you plan to reseed. If you have tough-to-kill weeds like nutsedge, start applying herbicide even earlier. Most post-emergent herbicides have a waiting period before you can plant anything.
Note: Don’t use a post-emergent with a weed barrier or pre-emergent component. It will prevent healthy germination of the grass seeds.
Smothering, solarization, and sheet mulching. Start these procedures at least two months before reseeding your lawn. While they don’t use chemicals to kill grass and weeds, they take longer to do the job.
Once you’re left with bare soil, preparing your lawn is pretty fast as the rest of the tasks will only take you a few days to accomplish.
FAQs about reseeding
Can you reseed your lawn in the winter?
While it may not be the best time, you technically can reseed your lawn in the winter. The process of laying down seed in late fall and winter is called dormant seeding. However, you won’t see results until spring.
How do you reseed a lawn?
Here’s a very short guide on how to reseed a lawn:
- Prepare the soil by killing grass and weeds, adding soil amendments, and then aerating.
- Spread the right grass seed on your lawn.
- Fertilize the seeds and cover them.
- Water your lawn and keep the seeds moist.
When should I reseed my lawn instead of overseeding?
You should reseed your lawn instead of overseeding if your lawn is severely damaged. The University of Massachusetts Amherst recommends a full lawn renovation if more than half of your current lawn is damaged or has been taken over by weeds.
Call a pro to reseed your lawn
When the time comes to renovate your lawn, you’ll want to do it properly so your new lawn won’t develop problems. If you’re unsure if you can reseed your lawn correctly, you shouldn’t hesitate to hire a professional to do it for you instead.
Lawn Love can connect you with a local lawn care pro who can reseed your lawn, fertilize your new grass, and mow it once it’s long enough. Call a pro through Lawn Love today.
