Overseeding 101: How to Repair Summer Lawn Damage Before Fall

Summer in Ontario is tough on lawns. Between scorching sun, backyard foot traffic, and the occasional drought, it’s common to see bare patches, thinning grass, or brown spots by late August. The good news? You don’t need to start from scratch.

Overseeding — the process of adding grass seed to your existing lawn — is one of the most effective ways to repair summer lawn damage and set yourself up for a lush, green yard next spring.

In this guide, we’ll break down the basics of overseeding, why late summer is the perfect time, and how to combine it with aeration for the best results.

🌱 What Is Overseeding?

Overseeding is the practice of spreading new grass seed directly over your existing lawn without tearing it up.

✔️ Fills bare patches
✔️ Thickens thinning turf
✔️ Introduces new, resilient grass varieties
✔️ Improves your lawn’s overall density and colour

When combined with aeration, overseeding ensures the seed reaches the soil and establishes strong roots.

🍂 Why Late Summer Is the Best Time for Overseeding in Ontario

In Ontario, late August through early fall provides the perfect conditions for overseeding:

• 🌡️ Cooler temperatures help grass seedlings establish without heat stress
• 🌧️ More rainfall means consistent soil moisture
• 🌱 Reduced weed competition as crabgrass and summer weeds begin to die off
• ❄️ Prep for winter — strong fall growth ensures a healthy rebound in spring

👉 Overseeding Ontario lawns in late summer gives you the best germination window of the year.

🔑 Step-by-Step: How to Overseed Your Lawn

1. Mow Low – Cut your grass shorter than usual (2–2.5 inches) to give seeds more access to soil.
2. Remove Debris – Rake up clippings, leaves, and thatch to create an open seedbed.
3. Aerate the Lawn – Core aeration loosens compacted soil and creates holes for seed-to-soil contact.
4. Spread the Seed – Use a broadcast spreader for even coverage, choosing seed varieties suited to Ontario’s climate.
5. Topdress Lightly – Apply a thin layer of compost or soil to protect seeds and improve germination.
6. Water Consistently – Keep soil moist with light watering 1–2x daily until seedlings are established.
7. Fertilize – Apply a starter fertilizer to feed new seedlings.

🌟 Overseeding + Aeration = Maximum Results

Aeration and overseeding go hand in hand:

• Aeration opens up the soil, relieving compaction and reducing thatch.
• Seeds fall into the holes, creating the perfect environment for root growth.
• Nutrients penetrate deeper, boosting germination rates.

👉 Pairing overseeding and aeration ensures your lawn recovers quickly from summer stress and grows back thicker than ever.

🏡 Overseeding Services in Ontario

At Contract Link, we provide professional overseeding and aeration services across Kitchener, Waterloo, Guelph, Cambridge, Hamilton, Brantford, and surrounding regions.

✔️ High-quality seed blends matched to Ontario’s soil and climate
✔️ Core aeration to maximize seed-to-soil contact
✔️ Starter fertilization for strong germination
✔️ Lawn health assessments to target thin and damaged areas

👉 Book Your Overseeding Service Today

Repair your summer lawn damage now — and enjoy a thicker, greener, healthier lawn next spring. 🌱🍂