When to Plant Sunflowers in Red Deer, AB – 2026
Published: April 27, 2026
Red Deer is in Canadian Zone 3b (central Alberta continental). Last spring frost averages May 28; first fall frost September 12; the growing season runs about 107 frost-free days. Plant sunflowers in Red Deer from june 1 through 15 (after last frost — calgary june 7, edmonton june 2)..
Sunflowers Planting Window for Red Deer, 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 Red Deer, AB specifically, the recommended planting window is June 1 through 15 (after last frost — Calgary June 7, Edmonton June 2).. Red Deer has one of the shortest growing seasons of any major Canadian city. Focus on cool-season crops that thrive below 20°C. Raised beds warm soil 4-6°C faster in spring — effectively extending the season by 2 weeks. Cold frames and row covers are essential tools.
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 Red Deer, AB
For Red Deer, AB (Canadian Zone 3b), 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 Red Deer
Sow method: direct sow after last frost. The steps below adapt the general planting advice for Red Deer, 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 Red Deer, AB
When can I plant sunflowers in Red Deer?
Plant sunflowers in Red Deer from june 1 through 15 (after last frost — calgary june 7, edmonton june 2). based on the city's Canadian Zone 3b. Last spring frost: May 28; first fall frost: September 12; frost-free growing season: 107 days.
What Canadian zone is Red Deer?
Red Deer is in Canadian Zone 3b (USDA equivalent 3a). The climate is central alberta continental. Red Deer has one of the shortest growing seasons of any major Canadian city. Focus on cool-season crops that thrive below 20°C. Raised beds warm soil 4-6°C faster in spring — effectively extending the season by 2 weeks. Cold frames and row covers are essential tools.
Are sunflowers winter-hardy in Red Deer?
Sunflowers are tender annuals — frost kills them at any age. Direct sow only after last frost when soil reaches 10°C.