When to Plant Collard Greens in Fredericton, NB
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.
Fredericton's Canadian Zone 5b (USDA 5a) St. John River valley climate is continental with maritime influence. Warmer summers than coastal New Brunswick, colder winters. 151 frost-free days support a broad range of warm-season vegetables when timed carefully.
Collard Greens Planting Calendar for Fredericton
Start seeds indoors: April 5–12
Transplant outdoors: April 19–29
Direct sow outdoors: April 19–29
Harvest window: June 18 – July 3
Minimum soil temperature: 7°C (45°F)
Days to harvest: 60–75 days
Sun requirement: Full sun to partial shade
Fall crop planting: July 30–August 9 (harvest September 28)
⚠ 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.
Fredericton Climate Notes
Fredericton's St. John River valley creates a warmer microclimate than surrounding uplands. The city has New Brunswick's most productive growing conditions for warm-season crops. Long daylight hours in June-July produce exceptional tomato and pepper quality.
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 Fredericton
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 Fredericton
The most common pest and disease pressure on collard greens in Fredericton 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.
Other New Brunswick Cities
Frequently Asked Questions
When do I plant collard green in Fredericton?
Fredericton's last spring frost is around May 10. Start seeds indoors April 5–12. Transplant outdoors April 19–29.
What Canadian hardiness zone is Fredericton?
Fredericton is in Canadian Zone 5b (USDA equivalent 5a). The St. John River valley continental maritime climate delivers 151 frost-free days from May 10 to October 8, which shapes every planting date in the local calendar.
How long is Fredericton's growing season?
Fredericton has 151 frost-free days — from May 10 in spring to October 8 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 Fredericton?
Yes. Container growing on balconies and decks is practical in Fredericton — 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 Fredericton?
Fredericton's average first fall frost is October 8. For a fall collard green crop, plant around July 30–August 9 so plants mature before the first killing frost.