When to Plant Gai Lan in Canada — Sow Dates by Region
Fast-maturing and genuinely well-suited to short Canadian seasons — but it bolts quickly in summer heat. Sow dates by region, built around spring and fall, not summer.
Gai lan (Chinese broccoli, also called kai-lan) is one of the fastest brassicas you can grow — 45 to 60 days from seed to harvest, well within even a compressed Prairie season. That speed is the whole appeal.
The catch is that it bolts fast once real summer heat arrives, the same way cilantro does. Grown in the cool stretches of spring and fall, it's easy and productive; pushed through July, it flowers before you can harvest much of anything.
Gai lan in Canada at a glance: Direct sow 2–3 weeks before last frost. Vancouver: mid-March. Toronto/Windsor: early-to-mid April. Ottawa/Montreal/Halifax: late April. Prairies: early-to-mid May. Matures in 45–60 days — sow spring and fall, skip midsummer, it bolts in the heat.
When should you plant gai lan where you garden?
Get your city's frost dates, indoor seed-starting dates, and this week's planting jobs — three free tools.
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🥦 Shop vegetable seeds at West Coast Seeds →Gai Lan Sow Dates Across Canada
| Region (City) | Zone | Last Frost | Spring Sow | First Fall Frost | Fall Sow (~8 wks back) |
|---|---|---|---|---|---|
| Coastal BC (Vancouver) | 8a | Mar 15 | Mar 1–15 | Nov 15 | Mid-late Sep |
| BC Interior (Kelowna) | 6b | May 5 | Apr 15–25 | Oct 5 | Early-mid Aug |
| Southern Ontario (Toronto) | 6b | Apr 20 | Apr 5–15 | Oct 15 | Mid-late Aug |
| SW Ontario (Windsor) | 7a | Apr 20 | Apr 1–10 | Oct 25 | Late Aug–early Sep |
| Eastern Ontario (Ottawa) | 5a | May 9 | Apr 20–30 | Oct 5 | Early-mid Aug |
| Quebec (Montreal) | 5b | May 9 | Apr 20–30 | Oct 5 | Early-mid Aug |
| Prairies (Calgary) | 3b | May 23 | May 1–10 | Sep 15 | Mid-late July |
| Prairies (Edmonton) | 4a | May 14 | Apr 25–May 5 | Sep 20 | Late July–early Aug |
| Prairies (Winnipeg) | 3a | May 19 | May 1–10 | Sep 22 | Late July–early Aug |
| Maritimes (Halifax) | 6a | May 10 | Apr 20–30 | Oct 15 | Mid-late Aug |
Common Gai Lan Problems in Canada
Bolting before much growth
Almost always a summer-heat sowing. Stick to spring and fall windows and this stops being a problem — it's the plant's normal response to the season, not a growing mistake.
Bitter flavour
Heat and dry stress toughen the leaves and stalks. Consistent water and cool-season timing keep it mild.
Flea beetles and cabbage worms
The usual brassica pests. Floating row cover from sowing onward handles both and adds a little frost buffer for early spring and late fall sowings.
Frequently Asked Questions
When should I plant gai lan in Canada?
2–3 weeks before last frost. Vancouver: mid-March. Toronto/Windsor: early April. Prairies: early-to-mid May.
Why does it bolt so fast?
Heat and day length trigger flowering, like cilantro. Grow it in spring and fall, skip midsummer plantings.
Is it good for a short season?
Yes — 45–60 days to maturity fits comfortably into even a Prairie spring window.