🌻 When to Plant Sunflower

When should I plant sunflower?

Plant sunflower outdoors 2 weeks after last frost. For a head start, start seeds indoors 2 weeks before your area's last frost date. Transplants can go out 1 week after last frost.

Is sunflower frost sensitive?

Yes — Sunflower is frost-sensitive and will be damaged or killed by temperatures at or below 32°F. Wait until all frost danger has passed and nighttime lows are consistently above 50°F.

What temperature does sunflower need?

Sunflower grows best between 60°F and 95°F. It can survive down to 50°F, but growth slows significantly below 60°F. Warm nights are especially important once fruiting begins.

How long does sunflower take to grow?

Sunflower typically takes 70–100 days from transplant (or direct sow) to first harvest.

Should I start sunflower seeds indoors?

Yes — start sunflower seeds indoors 2 weeks before your area's last expected frost date. This gives seedlings time to develop strong roots before outdoor conditions are ready.

Is it too cold to plant sunflower?

It is too cold to plant Sunflower outdoors when nighttime temperatures are falling below 50°F. Sunflower is frost-sensitive, so a single freeze will kill it — wait until your area's last frost date has passed and nights are reliably above 50°F. Use CanIPlant to check your local 7-day forecast and get a real-time answer for your ZIP code.

Is it too hot to plant sunflower?

Sunflower starts to struggle when temperatures climb above 95°F. As a warm-season crop, Sunflower enjoys heat but can experience blossom drop and reduced fruiting above 100°F. Consistent highs above that level may delay planting until temperatures moderate. CanIPlant checks your local forecast highs to flag this automatically.

Any tips for growing sunflower?

Direct sow preferred. Full sun and well-drained soil.