Dormant Seeding: Sowing Grass in Late Fall for a Spring Lawn

Late August to mid-September is the best time to seed a cool-season lawn. But life happens, and plenty of homeowners look out in November at bare spots they meant to fix. Superintendents have a trick for that: dormant seeding. You sow seed when it's too cold for it to sprout, it sits in the soil all winter, and it comes up early in spring on its own.

How it works

Grass seed needs warm enough soil to germinate. If you seed when soil temperatures are consistently below about 50 degrees, the seed stays dormant. Freezing and thawing over the winter works it into the soil and helps it make good seed-to-soil contact. When the soil warms in spring, it germinates, often earlier than you could have seeded in spring yourself.

When to do it

• After the soil is too cold for seed to sprout, typically after several hard frosts, usually from mid-November into early winter across most of the northern US.
• Before snow covers the ground is easiest, but some superintendents even seed onto light snow.
• Too early is the real risk. Seed that sprouts during a warm spell in November will be killed by the next hard freeze.

Which grasses work

Dormant seeding works with the cool-season grasses:

• Kentucky bluegrass: slow to germinate, so it benefits from the head start.
• Tall fescue: tough and drought tolerant.
• Perennial ryegrass: fast to germinate, good in mixes.
• Fine fescues for shade.

Use the same mix you'd use in fall. See our guide to choosing the right cool-season grass mix.

How to do it

1. Prepare the spot: rake out dead grass and loosen the top half inch of soil. On bare spots, a light layer of compost or topsoil helps.
2. Seed at the normal rate on the bag, or slightly higher, since some seed won't survive the winter.
3. Rake it in lightly so the seed is just covered, or roll it so it's pressed into the soil.
4. Don't fertilize now. Save that for spring, after the seedlings emerge.
5. No watering needed until spring, when the seedlings will need steady moisture.

What to expect

Expect some seed loss to birds, washouts on slopes and winter conditions. On steep areas, erosion blankets or straw help. In spring, the seedlings will need regular watering as they emerge, just like a fall seeding.

Don't combine it with spring crabgrass control

Most crabgrass preventers stop grass seed from germinating too. If you dormant seed, skip the spring pre-emergent on those areas or use a product labeled safe for new seedings. Our pre-emergent timing guide explains the details.

Dormant seeding isn't as reliable as a September seeding, but it's far better than waiting until May. On a golf course we used it every year on spots we couldn't get to in time, and it saved us weeks in spring.

Photo: Seed Mixer (13308283343).jpg) by USFWSmidwest, Public domain.

Related: Overseeding Your Existing Lawn: The Complete Fall Renovation Protocol