When to Plant Sunflowers in Moncton, NB – 2026
Published: April 27, 2026
Moncton is in Canadian Zone 5b (Fundy tidal-influenced maritime). Last spring frost averages May 10; first fall frost October 12; the growing season runs about 155 frost-free days. Plant sunflowers in Moncton from late may through early june..
Sunflowers Planting Window for Moncton, NB
Direct sow sunflower seeds after last frost when soil reaches 10°C / 50°F. Most zones: April–June. Warm-season annual — does not tolerate frost. Days to bloom: 70–100 days from seed.
For Moncton, NB specifically, the recommended planting window is Late May through early June.. Bay of Fundy proximity creates a unique tidal-influenced microclimate. Moncton's summer warmth surprises many — July-August temperatures reliably support tomato crops with early starting. The Petitcodiac River valley is particularly productive for warm-season crops.
Sunflowers are tender annuals — frost kills them at any age. Direct sow only after last frost when soil reaches 10°C.
Best Sunflowers Varieties for Moncton, NB
For Moncton, NB (Canadian Zone 5b), choose varieties rated for your zone or one zone colder for reliable winter survival. The Canadian-bred or tested varieties below perform well in New Brunswick conditions.
Tall (3 m) classic giant sunflower. 90 days to bloom — works in southern Ontario and BC; tight for Calgary/Edmonton.
Branching habit, 1.5 m tall, multiple golden-yellow blooms. 60 days. Excellent for short-season Prairies.
Cut-flower industry standard. 50-60 days. Successive sowings every 2 weeks for continuous Canadian blooms.
Branching pale yellow. 1.5-2 m tall. 90 days. Excellent for pollinators in Ontario and Quebec gardens.
60 cm container-friendly fully-double yellow blooms. 60 days. Works on Prairie balconies.
How to Plant Sunflowers in Moncton
Sow method: direct sow after last frost. The steps below adapt the general planting advice for Moncton, NB's climate and timing.
- →Direct sow sunflower seeds 2.5 cm (1 inch) deep, after the last frost when soil reaches 10°C (50°F).
- →Space giant varieties 60 cm (24 inches) apart; branching types 30 cm (12 inches); dwarf 20 cm (8 inches).
- →Choose a site with full sun (8+ hours) — sunflowers track the sun and lean toward shade.
- →Water consistently for the first 3 weeks; once established, water deeply weekly during dry periods.
- →Stake giant varieties at planting — adding stakes after the plant reaches 1 m (3 ft) damages roots.
- →Sidedress with balanced fertilizer when plants reach 60 cm (2 ft) tall — once is enough.
Frequently Asked Questions about Sunflowers in Moncton, NB
When can I plant sunflowers in Moncton?
Plant sunflowers in Moncton from late may through early june. based on the city's Canadian Zone 5b. Last spring frost: May 10; first fall frost: October 12; frost-free growing season: 155 days.
What Canadian zone is Moncton?
Moncton is in Canadian Zone 5b (USDA equivalent 5a). The climate is fundy tidal-influenced maritime. Bay of Fundy proximity creates a unique tidal-influenced microclimate. Moncton's summer warmth surprises many — July-August temperatures reliably support tomato crops with early starting. The Petitcodiac River valley is particularly productive for warm-season crops.
Are sunflowers winter-hardy in Moncton?
Sunflowers are tender annuals — frost kills them at any age. Direct sow only after last frost when soil reaches 10°C.