The Home Almanac

Planting dates for Ottawa

Frost dates and sow windows from the 30-year record at Ottawa Cda, the official station 3 km from Ottawa, Ontario.

Last spring frostApril 30
First fall frostOctober 6
Frost-free season158 days

Sow and transplant events for the staples, straight from this page.

Key windows for Ottawa (2026)

CropStart indoorsPlant out / sow
Tomato March 19 May 7
Pepper March 5 May 14
Peas March 26
Lettuce March 5 April 2
Carrot April 9
Bush beans May 7
Garlic (longer than the average season; use short varieties) Fall planted
Potato April 16

Mean-date planning windows, not guarantees; watch the local forecast at the shoulders. Method on the methodology page.

Ottawa planting questions

When is the last frost in Ottawa?

Around April 30, the 30-year mean date of the last spring frost at Ottawa Cda, the official station 3 km from Ottawa. Half of years see frost after the mean, so tender crops usually wait a week or more past it.

When can I plant tomatoes in Ottawa?

Start seeds indoors around March 19 and transplant around May 7, once nights hold above 10 C. The full 32-crop table on the planner computes every window for Ottawa.

How long is the growing season in Ottawa?

About 158 frost-free days on average, from roughly April 30 to October 6. Crops whose days-to-maturity exceed that window need transplants, short-season varieties, or season extension.

How this page was made

Every date above is computed from the Environment and Climate Change Canada Canadian Climate Normals at Ottawa Cda: the 30-year mean dates of last spring and first fall frost, with crop offsets from standard horticultural practice. Full method and crop sources: data and methodology. These are planning averages, not forecasts: half of years frost later than the mean, so harden off transplants and watch the local forecast at the shoulders of the season.

More for Ottawa: winter tire dates. Need every crop, or a different place? The full calendar covers 32 crops at 638 stations.