Zone 3 · Sunflower
Planting Sunflower in Zone 3
Helianthus annuus
✅ Sunflower thrives in zone 3 (hardy 2–11)
Can I plant today?
⏳ Too early to direct-sow
Last frost is in 4 weeks. Wait until soil warms.
Evaluated for April 27, 2026 ·
Zone's last frost
around May 15
Zone's first frost
around September 15
Bloom window
July – September
Peak bloom
August
Sun required
full sun
Mature height
72"
Spacing
18" apart
Type
annual
How to plant Sunflower in zone 3
Direct-sow after last frost, 1 inch deep.
Pair with these for continuous bloom
Sunflower peaks in August. These companions keep your bed in color before and after.
Want a full bed designed for zone 3?
Sign up free. GimmeBlooms builds a bloom-succession layout withSunflower and 3–5 perfect companions.
Design my bed →