When to Plant Sunflowers in Toronto, ON – 2026
Published: April 27, 2026
Toronto is in Canadian Zone 6b (Great Lakes temperate). Last spring frost averages April 20; first fall frost November 1; the growing season runs about 195 frost-free days. Plant sunflowers in Toronto from late may through early june (after victoria day)..
Sunflowers Planting Window for Toronto, ON
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 Toronto, ON specifically, the recommended planting window is Late May through early June (after Victoria Day).. Lake Ontario extends the growing season 2-3 weeks compared to inland Ontario. Toronto gardeners enjoy one of Canada's longest productive windows. Heirloom and heat-loving varieties that struggle farther north (eggplant, melons, sweet potato) succeed reliably here.
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 Toronto, ON
For Toronto, ON (Canadian Zone 6b), choose varieties rated for your zone or one zone colder for reliable winter survival. The Canadian-bred or tested varieties below perform well in Ontario 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 Toronto
Sow method: direct sow after last frost. The steps below adapt the general planting advice for Toronto, ON'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 Toronto, ON
When can I plant sunflowers in Toronto?
Plant sunflowers in Toronto from late may through early june (after victoria day). based on the city's Canadian Zone 6b. Last spring frost: April 20; first fall frost: November 1; frost-free growing season: 195 days.
What Canadian zone is Toronto?
Toronto is in Canadian Zone 6b (USDA equivalent 6a). The climate is great lakes temperate. Lake Ontario extends the growing season 2-3 weeks compared to inland Ontario. Toronto gardeners enjoy one of Canada's longest productive windows. Heirloom and heat-loving varieties that struggle farther north (eggplant, melons, sweet potato) succeed reliably here.
Are sunflowers winter-hardy in Toronto?
Sunflowers are tender annuals — frost kills them at any age. Direct sow only after last frost when soil reaches 10°C.