Southern Ontario & Quebec Vegetable Gardening Guide

Toronto, Ottawa and Montreal have a frost-free season of about 160–170 days and the warmest summers of the four regions, with July average highs around 26–27°C: good tomato and pepper country once the frost is over.

Frost dates, temperatures and precipitation are Environment and Climate Change Canada climate normals (1981–2010). Growing advice is checked against provincial agriculture departments and Canadian universities.

Frost dates and climate

Average dates of the last spring frost and first fall frost, and the frost-free period between them, at major stations in the region. The growing season is that frost-free period; choose varieties that mature within it.

What grows well here, and what struggles

Frost-tender crops go out only after the danger of frost has passed, hardier crops earlier. Starting seedlings indoors gives long-season crops a head start, and they need hardening off first. Row covers add frost protection at both ends of the season. Kale, cabbage and broccoli do well in cool autumn weather and stand light frosts; garlic is planted in fall.

Month by month

What our month guides recommend for Southern Ontario & Quebec. Each month links to the full guide.

• January: start indoors now?: Not yet: the Guelph calendar starts in February, other january work: Stock up on grow lights, heat mats, seed-starting mix and seed
• February: start indoors: Leeks, lettuce, eggplant , onions; peppers and asparagus late in the month, outdoors: Nothing
• March: start indoors: Peppers and onions early in March; tomatoes and brassicas late March, outdoors: Nothing yet
• April: indoors: Cucumbers and zucchini from mid-April, outdoors: Not yet: the ground is often workable only from late April to mid-May
• May: outdoors: Cool-season crops early to mid-May if you must, indoors or waiting: Harden off; most seedlings out by Victoria Day weekend
• June: sow outdoors: Warm-season vegetables from early June, also: Finish planting tomatoes and peppers; mulch
• July: sow or plant now: Little: it is hot for planting; try shade or containers, also: Water, weed, manage pests
• August: sow or plant now: Little; next planting round is September, notes: Water and weed through the heat
• September: sow or plant now: Another round of cool-season crops, also: Plant fall bulbs late in the month

Crop guides to start with

Guides for crops that appear in this region’s month-by-month plantings:

• Tomatoes
• Peppers
• Cucumbers
• Zucchini
• Green beans
• Peas
• Lettuce
• Spinach
• Carrots
• Beets
• Potatoes
• Garlic
• Kale
• Winter squash
• Onions

Weather and soil notes

These stations get about 790–1,000 mm of precipitation a year, and about 110–225 cm of snowfall, with Ottawa and Montreal the snowiest. Southern Quebec has no month guide of its own yet; follow the southern Ontario notes and check your own frost dates against the table.

Back to regional gardening in Canada, or see the Canada vegetable planting calendar.

References

• Environment and Climate Change Canada: Canadian Climate Normals 1981–2010 (frost dates, temperature, precipitation)
• Manitoba Agriculture: Agricultural climate of Manitoba
• University of Saskatchewan, Gardening at USask: Determining planting dates
• Dalhousie University Faculty of Agriculture, Extended Learning: Sowing seed (Garden Box series)
• University of Saskatchewan, Gardening at USask: Growing your own transplants
• Manitoba Indigenous and Northern Relations: A community gardener’s guidebook
• Manitoba Northern Healthy Foods Initiative: Starting seeds indoors
• Dalhousie University Faculty of Agriculture, Extended Learning: Managing the garden: season extension and frost protection
• University of Saskatchewan, Gardening at USask: Row coverings in no-till gardening
• Ontario Ministry of Agriculture, Food and Agribusiness: Growing strawberries for home gardens
• Dalhousie University Faculty of Agriculture, Extended Learning: Vegetable gardening in the fall (Garden Box series)
• Iowa State University Extension: What’s the difference between cool and warm season veggies?
• University of Illinois Extension: Planting a fall vegetable garden
• Alabama Cooperative Extension System: Basics of fall vegetable gardening
• University of Saskatchewan, Gardening at USask: Garlic
• Ontario Ministry of Agriculture, Food and Agribusiness: Garlic production
• Government of Saskatchewan: Garlic

Figures in the tables are the official averages named above. Every other statement is supported by at least three of these sources. The month-by-month notes summarise our own month guides, each of which lists its sources. All sources were checked on 24 October 2026.

Last reviewed: 24 October 2026