A fertilizer schedule for Ontario lawns
Most lawns in the GTA are fed at the wrong times of year, and the round that matters most is the one people skip.
Fertilizer is not a treatment you apply when the lawn looks tired. It is a schedule that follows what the plant is doing underground, and in Ontario that schedule is fairly specific.
What the grass is doing, month by month
Cool-season grasses grow in two pushes: a strong one in spring and a second in early autumn. In between, through July and August, they are surviving rather than growing. Feeding heavily during that survival phase pushes leaf growth the plant cannot support, which is how you get a lush lawn in June that collapses in August.
Feed the roots in autumn and the leaves take care of themselves in spring.
The rounds worth doing
- Late spring, once the lawn is actively growing and the first flush has passed
- Early summer, light, to carry it into the heat
- Early autumn, as growth resumes and roots start rebuilding
- Late autumn, before dormancy, and this is the important one
Why the late-autumn round matters most
Once top growth stops, the plant keeps working underground for several weeks. Nutrients applied then go into root development and carbohydrate storage rather than leaf. That stored energy is what the lawn draws on to green up in April without you doing anything.
Skip this round and you are relying entirely on spring feeding, which produces fast top growth on a weak root system. It looks good in May and fails in July.
How many rounds a GTA lawn actually needs
Three to four for most properties, and fewer if the lawn is healthy and the clippings are being managed well. More is not better. Excess nitrogen produces soft growth that is more attractive to disease and needs more mowing.
We price fertilization separately from maintenance for exactly this reason. You should only pay for the rounds your lawn needs, and that number is different from property to property.