When to Plant Collard Greens in Montréal, QC
Published: April 24, 2026 · Updated: April 27, 2026
Extremely cold-hardy leafy brassica — withstands temperatures to -10°C. Direct sow or transplant 3–4 weeks before last frost. Fall plantings produce the best-flavored greens after frost.
Montréal's Canadian Zone 5b (USDA 5a) St. Lawrence River valley climate is continental with cold winters and warm humid summers. The urban heat island extends the effective growing season by 1-2 weeks compared to surrounding areas — 162 frost-free days with some microclimate advantage for heat-loving crops.
Collard Greens Planting Calendar for Montréal
Start seeds indoors: March 27–April 3
Transplant outdoors: April 10–20
Direct sow outdoors: April 10–20
Harvest window: June 9 – June 24
Minimum soil temperature: 7°C (45°F)
Days to harvest: 60–75 days
Sun requirement: Full sun to partial shade
Fall crop planting: August 1–11 (harvest September 30)
⚠ Direct sow or transplant collard greens 3–4 weeks before last frost. Extremely cold hardy — withstands temps to 15°F. Can be grown as a perennial in Zones 8+. Fall planting produces the best-flavored greens.
Montréal Climate Notes
Montréal's urban heat island extends the effective growing season by 1-2 weeks versus surrounding areas. French vegetable gardening culture is strong — leeks (poireaux), shallots (échalotes), and heritage varieties are widely grown. Many Francophone Quebec gardeners source seeds from specialist heritage seed companies like Semences du Portage.
Growing Tips for Collard Greens
- Harvest outer leaves continuously once plants reach 10 inches — the central growing point produces for months.
- In Zones 8+ collard greens often overwinter and produce for 2–3 years as a perennial.
- Frost improves flavor dramatically — southern tradition is to wait for the first frost before harvesting.
- Blanch and freeze excess harvest — collard greens freeze beautifully and provide winter vitamins.
Companion Planting in Montréal
Pair collard green with Onion, Garlic, Dill, Celery for mutual benefit. Avoid planting near Tomato, Strawberry, Bean, which compete with or inhibit collard green growth.
Pests and Problems to Watch in Montréal
The most common pest and disease pressure on collard greens in Montréal comes from Cabbage Worm, Aphid, Flea Beetle, Cabbage Looper. Floating row covers through the first 4–6 weeks after planting block adult pests from laying eggs, and a weekly scouting routine catches infestations before they damage the crop.
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Frequently Asked Questions
When do I plant collard green in Montréal?
Montréal's last spring frost is around May 1. Start seeds indoors March 27–April 3. Transplant outdoors April 10–20.
What Canadian hardiness zone is Montréal?
Montréal is in Canadian Zone 5b (USDA equivalent 5a). The St. Lawrence valley continental climate delivers 162 frost-free days from May 1 to October 10, which shapes every planting date in the local calendar.
How long is Montréal's growing season?
Montréal has 162 frost-free days — from May 1 in spring to October 10 in fall. That is more than enough time to finish a full collard green crop (60–75 days to maturity) before the first fall frost.
Can I grow collard green in containers in Montréal?
Yes. Container growing on balconies and decks is practical in Montréal — choose a 5-gallon or larger dark-coloured container to warm the root zone, use a high-quality potting mix, and water daily during hot summer weather. In milder climates, containers extend both spring and fall windows by several weeks.
What is the first fall frost in Montréal?
Montréal's average first fall frost is October 10. For a fall collard green crop, plant around August 1–11 so plants mature before the first killing frost.