Timing is among the most consequential decisions in vegetable gardening. Start too early and seedlings sit in cold, wet soil that promotes rot and stunts roots. Start too late and short-season crops like brassicas fail to mature before autumn frosts cut the season short. A reliable planting calendar anchored to your local last-frost date removes much of the guesswork.
The schedules below are built around last-frost dates for Zones 3 through 7 — the range covering most of Canada's densely populated growing regions, from Manitoba and northern Ontario through the St. Lawrence Valley and into southern BC. Where the schedule differs meaningfully between zones, this is noted.
How to use this calendar: Find your approximate last-frost date from the Agriculture Canada plant hardiness zone map, then count backward or forward from that date using the weeks indicated for each crop.
Understanding Canadian growing zones
Agriculture and Agri-Food Canada's Plant Hardiness Zone system uses average minimum winter temperatures as the primary variable, but last-frost date in spring is the more practical reference for vegetable gardeners. The two are correlated but not identical.
Approximate last-frost dates by zone:
| Zone | Approximate last frost | Example locations |
|---|---|---|
| Zone 3 | Late May – early June | Winnipeg, Saskatoon, Thunder Bay |
| Zone 4 | Mid-May | Ottawa, Edmonton, Sudbury |
| Zone 5 | Early–mid May | Toronto (inner), Calgary, Halifax |
| Zone 6 | Late April – early May | Vancouver suburbs, Niagara, Windsor |
| Zone 7 | Mid-April | Greater Vancouver, Victoria, Saanich |
These are generalizations. Urban heat islands, proximity to large bodies of water, elevation, and slope aspect all shift local frost dates. The dates above should be treated as starting estimates to be refined through local observation over a few seasons.
February and March: Starting long-season crops indoors
In most Canadian zones, February and March are exclusively for indoor seed starting. The ground is frozen or waterlogged, and outdoor soil temperatures are far below what any vegetable seed requires for germination.
Crops to start indoors 10–12 weeks before last frost:
- Leeks — slow germination, benefit from the longest head start
- Onions from seed (not sets) — 10–12 weeks allows bulb sizing
- Celery and celeriac — require consistent warmth, prone to bolting if chilled
- Peppers — 10–12 weeks; in Zone 3–4, use shortest-day varieties like Ace or Beaver Dam
In Zones 3 and 4, starting peppers in late February is common practice because the growing season (roughly 100–130 frost-free days) barely covers full pepper maturity even with transplants that are 10 weeks old at planting.
April: Brassicas and first outdoor activities
April is when seed starting accelerates and, in Zones 6–7, direct sowing of cold-hardy crops becomes possible.
Crops to start indoors 6–8 weeks before last frost (typically April for most zones):
- Tomatoes — 6–8 weeks; earlier risks leggy transplants unless supplemental lighting is used
- Cabbage, broccoli, cauliflower, kale — 4–6 weeks; these tolerate some cold at transplant time
- Eggplant — 8–10 weeks; cold-sensitive, keep at 21–26°C for germination
In Zones 6–7, direct sowing in April is practical for:
- Spinach — germinates in soil as cool as 4°C
- Arugula — tolerates light frost once established
- Radishes — 25-day crops can yield multiple successions
- Peas — direct sow 4–6 weeks before last frost, can tolerate light frost
May: The main transplanting and sowing month
May spans the last-frost window for most of the country and is the busiest month in the garden calendar.
Cold-tolerant crops: transplant or direct sow as soon as soil is workable
- Broccoli, cabbage, cauliflower transplants
- Peas (direct sow in Zones 3–5 where April was too cold)
- Beets, Swiss chard, turnips — direct sow
- Lettuce — direct sow or transplant; bolt risk increases after soil temperature exceeds 25°C
- Carrots — direct sow; germination requires consistent moisture for 14–21 days
Warm-season crops: transplant after last frost
- Tomatoes — after last frost, when overnight soil temperature stays above 10°C
- Peppers — same timing as tomatoes, even more cold-sensitive
- Cucumbers, zucchini, squash — direct sow or transplant after last frost
- Beans — direct sow after last frost; soil should be at least 15°C
- Basil — transplant after nights consistently above 10°C
| Crop | Timing relative to last frost | Method |
|---|---|---|
| Tomatoes | At or 1–2 weeks after | Transplant |
| Peppers | 1–2 weeks after | Transplant |
| Cucumbers | 1 week after | Direct sow or transplant |
| Zucchini / summer squash | At or 1 week after | Direct sow |
| Beans (bush) | At last frost | Direct sow |
| Carrots | 3–4 weeks before last frost | Direct sow |
| Beets | 4 weeks before last frost | Direct sow |
| Peas | 4–6 weeks before last frost | Direct sow |
June and July: Succession sowing and crop monitoring
Once the main planting is complete, June and July focus on succession sowing — staggering plantings of fast-maturing crops to extend the harvest season rather than getting everything at once.
Crops suited to succession sowing every 2–3 weeks from June through mid-July:
- Radishes (25-day maturity)
- Lettuce (30–50 days depending on type)
- Bush beans (50–60 days)
- Cilantro — bolt-prone in heat; sow every 3 weeks for continuous harvest
- Beets (55–70 days) — second sowing in July for autumn harvest
In Zone 3–4, July is the last practical date for direct-sowing any crop with a maturity longer than 60 days if autumn frost arrives in mid-September. Days to maturity figures on seed packets are minimum estimates under ideal conditions — add 10–20% buffer for northern and inland locations.
August and September: Autumn crops and bed preparation
Cool-season crops sown in August mature in the cooler, shorter days of September and October, often with improved flavour — many brassicas and root vegetables develop more sweetness after light frosts.
In Zones 5–7, August plantings can include:
- Spinach — sown 6–8 weeks before first autumn frost
- Arugula — very frost tolerant once established, sow mid-August onward
- Kale — transplants or direct sow, tolerates hard frost to -7°C
- Asian greens (bok choy, tatsoi, mizuna) — bolt-resistant in cooler temperatures
- Garlic — plant in late September through October for the following year's harvest
Garlic: planting in autumn for summer harvest
Hardneck garlic varieties perform well across Canadian zones and require a cold period (vernalization) to form individual cloves. Planting takes place in September–October, after soil temperatures drop below 10°C but before hard freeze.
Plant individual cloves 5–8 cm deep, pointed end up, 15 cm apart. Mulch with 10–15 cm of straw after the ground starts to freeze to moderate temperature fluctuations. Scapes (flower stalks) form in late June–early July; removing them directs energy to bulb development. Harvest when the lower third of leaves have yellowed, typically in late July.
Garlic is one of the most forgiving crops in the Canadian garden. It requires minimal attention between planting and harvest, occupies beds during the off-season, and produces consistent yields even in Zone 3 conditions with adequate mulching.
