When to Plant Cabbage in Calgary, AB
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.
Calgary's Canadian Zone 4a (USDA 3b) semi-arid continental climate creates a short growing season with intense summer sun, chinook winds that cause rapid temperature swings, and frost possible in any month. At 1,048 metres elevation with only 112 frost-free days, variety selection under 65 days is essential.
Cabbage Planting Calendar for Calgary
Start seeds indoors: April 6–13
Transplant outdoors: May 4–14
Harvest window: July 3 – August 12
Minimum soil temperature: 7°C (45°F)
Days to harvest: 60–100 days
Sun requirement: Full sun (6+ hours)
Fall crop planting: June 23–July 3 (harvest August 22)
⚠ 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.
Calgary Climate Notes
Calgary is the most challenging major Canadian city for vegetable growing. Choose varieties under 65 days. Cold frames and row covers are essential, not optional. Chinook winds damage young plants in spring; hailstorms are a regular summer risk — have covers ready. The 1,048 metre elevation intensifies UV and accelerates soil drying, so drip irrigation and mulch are critical.
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 Calgary
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 Calgary
The most common pest and disease pressure on cabbage in Calgary 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 Alberta Cities
Frequently Asked Questions
When do I plant cabbage in Calgary?
Calgary's last spring frost is around May 25. Start seeds indoors April 6–13. Transplant outdoors May 4–14.
What Canadian hardiness zone is Calgary?
Calgary is in Canadian Zone 4a (USDA equivalent 3b). The semi-arid continental climate delivers 112 frost-free days from May 25 to September 15, which shapes every planting date in the local calendar.
How long is Calgary's growing season?
Calgary has 112 frost-free days — from May 25 in spring to September 15 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 Calgary?
Yes. Container growing on balconies and decks is practical in Calgary — 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 Calgary?
Calgary's average first fall frost is September 15. For a fall cabbage crop, plant around June 23–July 3 so plants mature before the first killing frost.