Why Planting Grass Seed in the Winter Works

No matter where you live or what kind of grass seed you’re planting, two things are absolutely critical. Good seed-to-soil contact and adequate moisture will get those seeds to sprout and fully establish.

There are several ways to reseed your lawn, but one tried-and-true way is rarely considered. It’s called winter seeding.

Late fall lawn work usually means raking leaves and coiling up garden hoses. Why not add lawn seeding to your list? Also known as dormant seeding, seeding late in the fall just before the ground freezes can free you from doing it in the spring.

How do I know so much about winter grass seed? I got my start in the professional turfgrass industry working for an international seed company. I helped the company develop its lawn seed division. Now I advise sports turf managers, lawn care professionals and property management companies on how to turn grass seed into lush turf.

Your lawn may be a candidate for winter seeding if you live where cool-season grasses like Kentucky bluegrass, fine fescues and perennial ryegrass grow, and soil temperatures drop below 40 degrees during the winter months. Here’s what you need to know.

What Is Dormant Seeding?

Dormant seeding involves sowing grass seed in late fall, understanding that it will not germinate right away. The seed remains dormant through the frigid winter months, then germinates in the spring when soils warm and the rest of your lawn begins to green up.

What Is the Optimal Time To Plant Winter Grass Seed?

The trick is planting your grass seed once soil temperatures are too cold to trigger germination.

You can pick up an inexpensive soil thermometer online or at your local garden center to track how warm or cold your soils are. If soils are hovering around 50 degrees, it’s still too soon to plant. Wait a couple of weeks and check soil temperatures again.

Temps can vary within your lawn depending on the type of soil; its proximity to patios, driveways, street curbs and other heat-absorbing surfaces; whether it’s in heavy shade or full sun. Once soils are consistently below 45 degrees, you’re good to go.

Dormant seeding works best when Mother Nature cooperates by adding a winter-long covering of snow shortly after sowing. The snow cover insulates the seed and keeps it from being eaten by birds or blown away by wind. Think of it as a layer of white, fluffy mulch.

What Is the Best Way To Winter Seed?

The steps aren’t much different than overseeding your lawn during the spring or fall. Here’s what to do  — and what not to do.

1. Choose a seed mixture with a high percentage of Kentucky bluegrass and fine fescues. Limit the amount of perennial ryegrass to 25% of the seed mix. Ryegrasses germinate in cooler soil temperatures and might emerge pre-maturely in the spring during an unseasonably warm spell.
2. Scratch bare ground and loosen the soil.
3. If needed, add soil to level any low spots.
4. Apply seed at 12 to 16 seeds per square inch or about four to five pounds per 1,000 square feet.
5. Lightly rake and tamp the seed firmly into the soil. It’s firm enough when your shoe leaves a shallow but noticeable imprint.
6. Skip the starter fertilizer application when dormant seeding. Wait until next spring when soil temperatures reach a consistent 50 degrees.
7. Water at the time of seeding. This can be problematic if you’ve already turned off your outside spigots. If so, use a watering can.
8. Don’t mulch winter-seeded areas. Wet, soggy mulch in the spring can cause germination and disease issues.
9. Don’t apply a pre-emergent crabgrass preventer to these areas in the spring. This will keep your seeds from germinating!

How to Care For Winter-Seeded Grass in the Spring

Follow-up care should begin once your seed germinates in spring. Keep the soil relatively moist (not muddy) and don’t let it turn powder dry. Light, frequent waterings as seedlings mature can be replaced with fewer waterings, but for longer periods.

Avoid mowing these areas the first two or three times you cut the rest of your grass. Once the establishment is well underway, go ahead and mow. Always make sure your mower blade is sharp.