How to Grow Sunflowers
Helianthus annuus
Big, cheerful, and foolproof from seed — a favorite with kids and pollinators.
About sunflowers
Sunflowers are about as easy as gardening gets: drop a seed in warm soil and stand back. They range from giant single-stemmed varieties topping eight feet to branching multi-bloom types for cutting. Beyond their cheer, they’re pollinator magnets and the seed heads feed birds well into fall.
When to plant and harvest sunflowers
Timing is relative to your frost dates. Find your USDA zone for exact dates, or browse the month-by-month calendars.
Start seeds indoors
Optional, 2–3 weeks early
Transplant outdoors
After last frost (handle roots gently)
Direct sow
1 week after last frost where they’ll grow
Harvest
Late summer (blooms or seeds)
How to grow sunflowers step by step
- 1
Direct-sow 1 in deep where plants will grow — they resent transplanting.
- 2
Thin to the spacing for your variety; giants need more room.
- 3
Stake tall types in windy sites.
- 4
Stagger sowings every 2 weeks for continuous blooms.
- 5
Leave seed heads for birds, or cover and dry them to harvest seeds.
Common problems growing sunflowers
⚠ Toppling in wind
Tall varieties need staking or a sheltered spot.
⚠ Birds/squirrels eating seedlings
Protect emerging seedlings with netting or cover.
⚠ Drooping heads
Normal as seeds mature and the head gets heavy.
✗ Keep away from
🧺 Harvesting sunflowers
For cut flowers, snip when the bloom just opens, in the cool morning. For seeds, let heads dry on the stalk until the backs turn brown, then cover to beat the birds.
Sunflowers: frequently asked questions
How tall do sunflowers grow?＋
It depends entirely on the variety — from compact 2-foot types to towering giants over 10 feet. Check the seed packet.
Do sunflowers really follow the sun?＋
Young flower buds track the sun (heliotropism), but mature blooms typically settle facing east.
Grow sunflowers in your zone
See exactly when to plant and what else to grow alongside sunflowers, tailored to your USDA hardiness zone.
