Dormant seeding is the process of planting grass seed in winter. While the seed won’t germinate in cold temperatures, it will be set up for success when spring temperatures arrive. If timed correctly, dormant seeding can be very effective. For best results, follow these tips for dormant seeding success:
- Wait for soil temperatures below 40 degrees Fahrenheit.
- Seed in late winter. Seeds cast in February or March have a higher success rates.
- Seed on bare ground. Do not seed on top of deep snow.
- If possible, use a rake to lightly cover grass seeds with soil.
- Do not use crabgrass preventers or other pre-emergent herbicide in spring.
If you have missed the window for fall seeding, which most cool-season grasses benefit from, winter seeding is the next-best option. Tall Fescue, Kentucky Bluegrass, and Perennial Ryegrass all do very well when seeded in winter.
5 Dormant Seeding Tips
Waiting to seed in spring can cause weeds and invasive grasses to get a head start on your grass seeds. By seeding during winter, you ensure your seedlings sprout as soon as temperatures warm up enough to trigger germination. To grow a lush yard by seeding over winter, do the following:
Check Soil Temperature
Wait to seed until soil temperatures are 40 degrees Fahrenheit or lower. This ensures that the soil temperature is low enough that a brief thaw will not cause seeds to germinate, only to be killed by the next cold snap.
- Cast seed when soil temperatures are 40℉ or colder.
- Check soil temperatures in your area using a soil temperature map.
- As a rule of thumb, soil temperatures are 10 degrees cooler than daytime air temperatures.
An added benefit of seeding during the winter months is that the ground naturally cracks and heaves. Seeds enter the soil through these cracks. This creates better seed-to soil-contact and increases germination rates.
Wait for Late Winter
Seeds cast in December and January have around a 50% chance of sprouting. Meanwhile, grass seed spread in February or March have success rates closer to 75%. For this reason, plan your winter seeding well after the new year.
Seed on Bare Ground
When possible, wait for thaws to clear snow before overseeding. Grass spread on snow is easy prey for birds and rodents. Additionally, when snow melts, it can carry any grass seed that was on top of the snow away with water runoff.
Seed in bare patches whenever possible, or use a snow blower or shovel to clear the ground. If you do seed on top of snow, make sure there is less than 1 inch of snow, otherwise most of your seed will go to waste before it ever reaches the soil.
Protect Your Grass Seed
Squirrels, mice, and birds are desperate for food during winter and grass seed looks like a free meal to them. One of the best winter lawn care tactics is to make sure any grass seed you spread is covered with a thin layer of soil, to keep out scavengers.
When possible, use a garden rake to loosen the soil surface before casting seed. Then, once the seed is on the ground, cover it with up to 1/2 inch of soil. This acts as a shield from opportunistic animals and promotes improved soil contact for the seeds. As the soil settles around the seeds over the winter, it provides the optimal conditions for sprouting in spring.
Pause the Pre-Emergent Herbicide
If you’ve overseeded during winter, do not apply any crabgrass preventers or pre-emergent herbicides in spring. These products are designed to kill seeds just as they sprout, and they’re not selective. They’ll kill off all your grass seeds and undo your winter work.
Wait until the grass has sprouted and has grown tall enough that it needs it first mowing (3–4 inches) before applying pre-emergent herbicides. This way, you’ll preserve your yard and still be able to apply pre-emergent in time to prevent chickweed and other late spring perennial weeds.
What is the Best Grass Seed for Dormant Seeding?
Cool-season grasses benefit the most from dormant seeding. These grasses typically germinate when soil temperatures rise above 55 degrees Fahrenheit. The cool-season grasses you should seed with in winter are:
- Tall Fescue
- Perennial Ryegrass
- Kentucky Bluegrass
Although fall is traditionally the best time to seed cool-season grasses, winter is the second-best option. These species experience a growth spurt in cool temperatures and will take advantage of the first thaw. If they are seeded later in spring, cool-season grasses may struggle to establish themselves. They may even die when exposed to summer heat. If you were too busy to get to it in fall, winter is the best time to seed your lawn.
How to Prevent Crabgrass after Dormant Seeding?
Many lawn care experts use pre-emergent herbicides to stop crabgrass from sprouting in spring. The problem with this is pre-emergents will also stop your grass seed from growing. Instead, try these solutions:
- Use a weed spray with Quinclorac that will kill crabgrass but won’t harm desirable grass.
- Hand pull crabgrass as it sprouts.
- Fertilize in spring to promote a healthy lawn.
A thick lawn will naturally help to choke out crabgrass. One of the excellent things about the dormant seeding process is that it causes your lawn to grow thicker earlier in spring, which keeps weeds at bay. You can expect to have fewer crabgrass problems after seeding in winter.
What is Snow Seeding?
Snow seeding is the practice of casting seed on top of snow during winter. This generally has lower germination rates than seeding on bare soil. Seed on snow is more prone to being eaten by animals or being washed away with snowmelt.
- Avoid seeding on top of snow when possible.
- Never cast seed on snow deeper than 1 inch.
- When possible, clear snow from patches of yard you wish to seed.
If the snow is less than 1 inch deep, snow seeding can be effective, because the seed is more likely to be carried down to the soil as the snow melts. Do not seed on top of deep snow, because your success rate will be very low, wasting seed, time, and money.
The Best Way to Overseed in Winter
For the best success with dormant seeding, seed with a cool season grass when soil temperatures are below 40 degrees Fahrenheit. To increase the germination rate of the grass seed, overseed in February or March, seed on bare soil, cover the seed with loose soil to protect it from animals, and do not apply any pre-emergent herbicides to your lawn in spring.
By seeding in winter, you will have new grass sprout as soon as temperatures begin to warm. You’ll have mature grass by late spring, while spring-seeded lawns are still just sprouting. Dormant overseeding can turn a thin or patchy yard into a beautiful green paradise.