When to Plant Sunflowers in Edmonton, AB – 2026
Published: April 27, 2026
Edmonton is in Canadian Zone 4a (continental boreal). Last spring frost averages May 20; first fall frost September 25; the growing season runs about 128 frost-free days. Plant sunflowers in Edmonton from june 1 through 15 (after last frost — calgary june 7, edmonton june 2)..
Sunflowers Planting Window for Edmonton, AB
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 Edmonton, AB specifically, the recommended planting window is June 1 through 15 (after last frost — Calgary June 7, Edmonton June 2).. Edmonton's long summer days (18+ hours of daylight at peak) accelerate crop development 20-30% faster than the same variety at southern latitudes. The North Saskatchewan River valley provides a sheltered microclimate measurably warmer than surrounding uplands. Short-season tomato varieties ripen reliably thanks to the long daylight.
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 Edmonton, AB
For Edmonton, AB (Canadian Zone 4a), choose varieties rated for your zone or one zone colder for reliable winter survival. The Canadian-bred or tested varieties below perform well in Alberta 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 Edmonton
Sow method: direct sow after last frost. The steps below adapt the general planting advice for Edmonton, AB'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 Edmonton, AB
When can I plant sunflowers in Edmonton?
Plant sunflowers in Edmonton from june 1 through 15 (after last frost — calgary june 7, edmonton june 2). based on the city's Canadian Zone 4a. Last spring frost: May 20; first fall frost: September 25; frost-free growing season: 128 days.
What Canadian zone is Edmonton?
Edmonton is in Canadian Zone 4a (USDA equivalent 3b). The climate is continental boreal. Edmonton's long summer days (18+ hours of daylight at peak) accelerate crop development 20-30% faster than the same variety at southern latitudes. The North Saskatchewan River valley provides a sheltered microclimate measurably warmer than surrounding uplands. Short-season tomato varieties ripen reliably thanks to the long daylight.
Are sunflowers winter-hardy in Edmonton?
Sunflowers are tender annuals — frost kills them at any age. Direct sow only after last frost when soil reaches 10°C.