Dormant Grass Seeding explained by a turfgrass producer

Semis de gazon en dormance

đŸŒ± Dormant Grass Seeding: How It Works (and Why It’s Harder Than You Think)

Dormant seeding involves spreading grass seed in late fall or early winter when the soil is cold enough to prevent germination. The seeds “hibernate” under the snow and then take advantage of moisture and quick soil warming in the spring, germinating earlier than traditional spring seedings. The result: faster establishment by a few weeks and better competition against spring weeds (University of Minnesota Extension, 2024).

However, with climate change, mid-winter thaws are much more frequent than they used to be, often damaging dormant seedings. After eight years as a sod farm, we have stopped using this method because of the growing risk of failure.
Still, we’ll walk you through what dormant seeding is, how it’s done, and why it remains an interesting—but risky—option for some homeowners.

When to Do It (for Quebec / Northeastern Regions)

Aim for late October to mid-November, as long as the soil isn’t frozen but cold enough to prevent germination—ideally below 10 °C (50 °F). Many university guides recommend soil temperatures between 4–7 °C (40–45 °F) and average air temperatures under 10 °C (Cornell University CALS, 2023).

In colder regions, another short window may appear in late winter (late February or early March) if the ground is bare and freezes overnight. The key: never seed over snow and avoid extended warm spells, which can trigger premature germination (University of Minnesota Extension, 2024).

Benefits and Risks

Theoretical Advantages

  • Earlier spring growth (2–3 weeks sooner than traditional spring seeding).

  • Flexible scheduling: soil prep can be done in fall when conditions are dry instead of waiting for wet spring weather.

  • Reduced weed pressure at germination (University of Nebraska–Lincoln Extension, 2024).

These advantages sound appealing in theory. Unfortunately, in practice, our experience has repeatedly shown that the risks increasingly outweigh the benefits.

Major Risks

Success varies by winter (protective snow cover = good; alternating freeze-thaw cycles = bad). Because each winter brings unique conditions—thanks to Mother Nature—it’s difficult to predict results. With climate change, mid-winter warm-ups are more common, and this makes dormant seeding much harder to succeed consistently.

Seed mortality is also higher than for a traditional late-summer seeding, so plan for heavier seeding rates (Cornell University CALS, 2023), or even be prepared to reseed the entire area in spring if failure occurs.

Step-by-Step Process (University-Recommended Method)

1. Prepare the Seedbed

Mow short (≈ 2 inches / 5 cm), rake to expose soil, then lightly dethatch or aerate to create 6–8 mm of loose soil. The absolute goal: good seed-to-soil contact (University of Minnesota Extension, 2024).

2. Choose the Right Seed Mix

For Canadian residential lawns: Kentucky bluegrass as a base, fine fescues for shade/drought tolerance, and a bit of perennial ryegrass for quick coverage and germination (Cornell University CALS, 2023).

3. Adjust Seeding Rates (Increase for Dormancy)

  • Kentucky bluegrass: about 3–4 lb per 1000 ftÂČ (≈ 1.5–2.0 kg / 100 mÂČ).

  • Tall fescue: about 9–12 lb per 1000 ftÂČ (≈ 4.5–5.8 kg / 100 mÂČ).
    These higher rates include the +50 % increase recommended to offset winter seed loss (University of Nebraska–Lincoln Extension, 2024).

4. Spread and Lightly Incorporate

Apply in two crossed passes, then lightly rake or roll to cover the seed 3–6 mm deep without burying it. On slopes, use a thin layer of clean straw mulch to reduce erosion (University of Nebraska–Lincoln Extension, 2024).

5. Minimal Watering

The soil should be moist but not soaked when seeding. After that, leave it undisturbed. In spring, start light and frequent watering if rainfall is insufficient (University of Minnesota Extension, 2024).

6. Spring Management

Wait until after the first mowing before using any herbicide. Avoid standard pre-emergent herbicides that inhibit young grass. If one is necessary, use Siduron (Tupersan), which is compatible with new seedlings (University of Nebraska–Lincoln Extension, 2024).

Quick FAQ

Can I do it on a dense lawn? Dormant seeding works best on bare or thinned patches; on a thick lawn, seed-to-soil contact is poor (University of Minnesota Extension, 2024).

What if a warm spell causes germination in November? Seedlings that sprout too early usually die afterward, which is why waiting until the soil is cold enough is critical (Cornell University CALS, 2023).

Dormant or late-summer seeding? For cool-season grasses, late August to mid-September remains the gold standard. Dormant seeding can be a backup option when that window is missed—but remember the growing risk of failure (University of Nebraska–Lincoln Extension, 2024).

Common Mistakes to Avoid

  • Seeding too early (early October during warm weather) → premature germination and winter kill before roots mature.

  • Seeding over snow → drift, runoff, and bird feeding.

  • Forgetting to increase the seeding rate for winter losses.

  • Skipping soil preparation (no raking or aeration) → poor seed-to-soil contact (University of Minnesota Extension, 2024).

📚 References

Older post

Back to tips