Flower · Asteraceae
When to plant sunflowers
Annual sunflowers are warm-season plants and are not frost-tolerant. Sow after damaging frost risk has eased, in a sunny position with well-drained soil.
Sow direct
1 week after
Counted from your last spring frost.
Days to flowering (estimate)
70-100
From sowing to flowering; cultivar and conditions matter.
Frost tolerance
Tender
How much cold the plant itself will take.
Choose a place for estimated dates and local climate checks.
Timing, in frost-relative terms
These offsets are the starting assumptions used by our calendar for sunflowers. They do not establish suitability in every climate. Your seed packet, cultivar and local growing advice take priority; in frost-free places the calendar uses monthly temperature patterns instead.
- Sow direct 1 week after the last frost.
- Expect 70–100 days to maturity, counted from sowing.
- Sow again every 14 days for a continuous supply.
Getting the timing right
Mature heights range from compact plants to giants. Check the packet before placing them near paths, smaller crops or an exposed boundary.
Frost tolerance
Check the named variety and local forecast before exposing young growth. The catalog cold-damage figure is a reference, not a guarantee: plant age, acclimatisation, wind and the duration of a freeze affect damage.
Classified as tender, with a catalog cold-damage reference of 0°C (32°F)32°F (0°C). Exposure duration, growth stage and acclimatisation change cold tolerance.
Before you plant sunflowers
Use the calendar to plan ahead, then check the conditions in your own garden.
- Measure the soil at sowing depth. Aim for at least 12°C (53.6°F); the calendar estimates soil warmth from air temperatures and cannot measure your bed.
- Check the local overnight forecast before planting out. Delay planting or keep protection ready if frost is forecast, even after the historical last-frost date.
- Use the maturity range on your seed packet when choosing a variety. Cold, short days and transplant stress can make harvest later than the calendar estimate.
Choose a sunflower for your space
Mature heights range from compact plants to giants. Check the packet before placing them near paths, smaller crops or an exposed boundary.
Keep seedlings watered while roots establish. Established plants can tolerate dry conditions better than newly germinated seeds, so drought tolerance is not a reason to leave the seedbed dry.
If you want wildlife value, leave suitable seedheads for birds. If you want cut flowers or edible seed, choose a variety intended for that purpose.
Growing in a container
Choose a dwarf variety for pots and provide drainage; large varieties need considerably more root room and protection from wind.
Further reading: NC State Extension: annual sunflower . General crop guidance; local dates on this site are calculated separately. Source checked 18 September 2026 by Safe to Plant; this is not an expert review.
How the dates are calculated and their limits · Keep a growing record · Report a local discrepancy