Aeration & overseeding

What you get

• Core aeration across the whole lawn
• Overseeding with a sun or shade mix to suit your yard
• Extra seed on thin and bare patches
• Watering instructions for the first few weeks
• First cut on the new grass done at the right height

Why aerate

A lot of Guelph sits on heavy, clay-based soil, and years of mowers and foot traffic pack it down. Water runs off, roots stay shallow and the lawn thins out. Core aeration pulls small plugs of soil out of the lawn so air, water and seed can get down to the roots. The plugs break down on their own in a week or two.

Why overseed right after

The holes left by aeration are the best seedbed a lawn will ever have. Seed that lands in them is protected and in contact with soil, which is what it needs to sprout. Overseeding without aerating first works a lot less well.

The window: late August to mid-September

This is when new grass has its easiest start in Guelph. The soil is still warm from summer, the nights are cooler, there's usually more rain, and crabgrass and other summer weeds are dying back instead of competing. Spring seeding works, but the new grass then has to survive its first summer right away.

After seeding, keep it damp until it comes up, usually 10 to 14 days. The City of Guelph has offered permits for extra watering on new seed in past years, so check before you start.