Lawn by Season

Ontario Lawn Care Guide

Canada's most populous province with a humid continental climate. Hot summers and cold winters with 5–6 months of lawn growing season.

Climate Zone: Great Lakes & Ontario

Humid continental climate moderated by the Great Lakes. Four distinct seasons with hot humid summers and cold snowy winters. Toronto, Ottawa, Hamilton, London, and Kitchener. Growing season of 5–6 months. Most populous Canadian lawn market.

Key challenge: Hot humid summers promoting brown patch and dollar spot. Heavy clay soils in many Ontario cities causing compaction and drainage issues. Winter kill in exposed areas.

Ontario Lawn Care by Season

Cities in Ontario

Compatible Grasses

Climate Overview for Ontario

Winter Low-15°C to -25°C
Summer High25°C to 32°C
Growing SeasonApril to October (6 months)
Frost-Free PeriodMid-May to mid-October
Annual Rainfall700–850mm
Annual Snowfall100–200cm (more in Ottawa)

Ontario Lawn Care Calendar

January
DormancyOrder spring supplies before April rush.
February
Plan springBook aeration. Research soil amendments.
March
Thaw beginsStay off wet, saturated soil.
April
Assess damageRake snow mould. Fertilise late April if soil at 10°C.
May
Overseed and pre-emergentCrabgrass pre-emergent when forsythia blooms. Overseed thin areas.
June
Weekly mowingWater as needed. Broadleaf weed control.
July
Summer stress managementAllow dormancy in heat. Watch for brown patch.
August
Grub watchApply nematodes. Overseed prep late August.
September
Prime renovationAerate, overseed, fall fertiliser.
October
WinteriserApply late October. Remove all leaves.
November
Final mowCut to 60–65mm. Complete leaf removal.
December
Full dormancyPrevent ice damage. Avoid salt on lawn.

Frequently Asked Questions

What is the best grass for Ontario (ON)?

Kentucky Bluegrass for most Ontario lawns — it handles the hot summers and cold winters well. Fine Fescue for shaded areas. Tall Fescue is gaining popularity in warmer southern Ontario (Windsor, Hamilton) for low-maintenance, drought-tolerant lawns.

When does lawn season start in Ontario?

Late April in Windsor and Hamilton; early May in Toronto and Kitchener; mid-May in Ottawa. Watch for soil temperature reaching 10°C as the reliable indicator.

Does Ontario have water restrictions for lawns?

No province-wide rules. Some municipalities impose odd/even watering days during summer dry spells. Toronto and Ottawa occasionally implement restrictions. Check your local municipal website.

What are the most common lawn problems in Ontario?

Grubs (European Chafer and Japanese Beetle) are the #1 pest. Brown patch and dollar spot in humid summers. Crabgrass and dandelion pressure is heavy. Ontario’s cosmetic pesticide ban means cultural practices are the primary defence.

When should I apply winteriser in Ontario?

Late October in most of Ontario; mid-October in Ottawa where winter arrives earlier. This is the single most important fertiliser application of the year.

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