Should You Water Dormant Grass Seed During a Dry Winter?

The intent of dormant grass seeding is to get a jump start on growing cool-season grass to fill in thin or patchy areas of a lawn. Part of the appeal is that you don’t need to water your seeds if the weather cooperates. In snowy regions, snowpacks insulate the seed so that it stays cool and dormant until the spring thaw. Even in areas where the snow melts, that should provide enough moisture to the soil. 

We reached out to Markis Hill, a horticulture agent and turf specialist at the Kansas State Research and Extension, for his expertise on dormant seeding and lawn care. He explains that, when it comes to watering your dormant grass seed, there’s a bit of nuance when the seasons don’t unfold as expected. Here's what you need to know about how to water dormant grass seed.

How Much and How Often Should You Water Dormant Grass Seed?

Ideally, not at all over the winter. But many regions don’t hold snow like they used to, which can be a challenge to dormant seeding. Spurts of warm weather and a dry fall may require some light watering. You want the soil to be damp, but not soggy. 

“If it’s been super dry for weeks and you know there hasn’t been a recent snow melt, and you do start to have days with warm temperatures, that’s when you should probably start thinking about watering,” Hill says, adding that if you can see the wind blowing dust, it’s time to water.

And that watering comes with a catch. “There’s always that risk that you’re benefitting the weeds. Henbit deadnettle and dandelions might get a jump start on some of your grass areas because they’re in the middle of their lifespan,” Hill says. 

Related: The Winter Watering Mistake That Can Wreck Your Grass

Do Watering Needs Change as Dormant Seeding Grows?

The big change is when the seeds are no longer dormant. In this stage, when temperatures are between 40 and 50 degrees during the spring thaw, the seeds need the most moisture. Hill says this is usually when snowmelt or spring rains help. If the weather isn’t cooperating, it’s time for manual watering.

Once the seed is established and growing a couple of inches, it’s time to help root growth. You don’t want to water too much, as overly moist soil promotes disease now. But a consistent weekly soak will get moisture to the roots, promote growth, and allow the topsoil to dry between waterings.

How Is Dormant Grass Seeding Different From Regular Grass Seeding?

Consider dormant seeding your lawn more of a repair than a build. Dormant seeding is a good way to overseed thin lawns and help establish your early- and late-season grasses like Kentucky bluegrass and Fescue. Hot-weather grasses like Bermudagrass and Zoysiagrass can be seeded in the spring to mature before summer’s peak heat and lack of water. Lawns often include a mix of both grasses.

The freeze-thaw cycles of late winter help the dormant seed nestle down and make contact with the soil, and germinate upon the spring thaw. That gives these seeds a jumpstart of about two to four weeks on spring-sown seeds.

Regular grass seeding in the spring takes advantage of the prime mix of conditions when the frosts are over, rainfall keeps soil moist, and the longer days provide more sunshine to promote growth.

Related: Should You Water Your Lawn in Winter? Most Homeowners Get This Wrong

Can You Dormant Seed in Late Winter?

Fall lawn care work often includes dethatching grass and drilling cores for better aeration, all of which gives dormant seeds space to contact the soil and take root. Dormant seeding is often seen as lawn care’s last step of the year. 

However, dormant seeding in February and March can be successful, too. Where this will work depends on the weather, and there’s always a chance it won’t cooperate. The magic temperature range seems to be consistently below 40 degrees.

Hill’s own writing on dormant seeding success cites opportunities for February seeding because “seeds are exposed to the elements and predators for a shorter amount of time while also having enough time to grow and mature before the heat of summer arrives.”

Related: I Use This Simple Test to Tell if My Lawn is Dead or Dormant

Be Prepared for Dormant Seeding to Fail

Hill reminds us that there’s no guarantee that dormant seeding will work. Watering alone isn’t enough to counter wild swings in temperatures or uncooperative weather that triggers early germination, followed by deadly freezes.

In this case, Hill offers a silver lining. “If anything, you've given a lot of seed to the birds, and they will be very happy. And you know, if the birds think that there’s food in your yard, they’ll revisit,” he says. “That’s a pest treatment you didn’t have to pay for.”