When to Plant Cabbage in Québec City, QC
Published: April 24, 2026 · Updated: April 27, 2026
Extremely cold-hardy brassica — survives temperatures as low as -7°C (20°F). Start indoors 6–8 weeks before last frost, transplant 2–4 weeks before last frost, and also plant for fall harvest.
Québec City's Canadian Zone 4b (USDA 4a) cold continental climate is one of Canada's shorter growing seasons at 138 frost-free days. Careful variety selection under 65 days is essential for warm-season crops, and cold frames and row covers extend both ends of the season significantly.
Cabbage Planting Calendar for Québec City
Start seeds indoors: March 27–April 3
Transplant outdoors: April 24–May 4
Harvest window: June 23 – August 2
Minimum soil temperature: 7°C (45°F)
Days to harvest: 60–100 days
Sun requirement: Full sun (6+ hours)
Fall crop planting: July 8–18 (harvest September 6)
⚠ Start cabbage indoors 6–8 weeks before last frost. Transplant 2–4 weeks before last frost. Very frost tolerant — withstands temperatures as low as 20°F. Also plant in late summer for fall harvest.
Québec City Climate Notes
Québec City gardeners must choose varieties under 65 days for warm-season crops. Cold frames and row covers extend the season by 4-6 weeks on each end. A 4-6 week indoor head start is essential. Cool-tolerant crops (peas, brassicas, root vegetables, hardy greens) are the backbone of productive gardens here.
Growing Tips for Cabbage
- Space plants 18 inches apart — crowding reduces head size and promotes fungal disease.
- Side-dress with nitrogen 3–4 weeks after transplanting to support rapid leaf formation.
- Harvest when heads feel firm; leave the root ball in the ground and small secondary heads may form.
- Fall cabbage sweetens after light frost — one of the best-tasting garden crops when harvested in October.
Companion Planting in Québec City
Pair cabbage with Onion, Dill, Celery, Beet for mutual benefit. Avoid planting near Tomato, Strawberry, Pepper, which compete with or inhibit cabbage growth.
Pests and Problems to Watch in Québec City
The most common pest and disease pressure on cabbage in Québec City comes from Cabbage Worm, Cabbage Looper, Aphid, Flea Beetle. 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.
Other Quebec Cities
Frequently Asked Questions
When do I plant cabbage in Québec City?
Québec City's last spring frost is around May 15. Start seeds indoors March 27–April 3. Transplant outdoors April 24–May 4.
What Canadian hardiness zone is Québec City?
Québec City is in Canadian Zone 4b (USDA equivalent 4a). The cold continental climate delivers 138 frost-free days from May 15 to September 30, which shapes every planting date in the local calendar.
How long is Québec City's growing season?
Québec City has 138 frost-free days — from May 15 in spring to September 30 in fall. That is more than enough time to finish a full cabbage crop (60–100 days to maturity) before the first fall frost.
Can I grow cabbage in containers in Québec City?
Yes. Container growing on balconies and decks is practical in Québec City — 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 Canadian Zone 3–4, a sheltered south-facing location adds 2–3 weeks to the effective season.
What is the first fall frost in Québec City?
Québec City's average first fall frost is September 30. For a fall cabbage crop, plant around July 8–18 so plants mature before the first killing frost.