Plant Sunflowers in Zone 7a
Seed-starting, transplant & harvest dates for USDA Zone 7a
Zone 7a averages 198 frost-free days, running from a last spring frost around April 10 to a first fall frost around October 25. Sunflowers needs roughly 80 days from planting out to first harvest, so it uses about 40 percent of that window. Sunflowers is a half-hardy crop, which is what decides where in the window it belongs.
Sunflowers resents transplanting and hates cold soil, so direct sow around Apr 17, after the Zone 7a last frost has passed and the soil has warmed. At 80 days to harvest, a 198-day Zone 7a season has room for about 2 sowings, so stagger them rather than planting everything at once.
Fall planting: sunflowers in Zone 7a
Sunflowers has no useful fall window in Zone 7a. Sunflowers need a long run of warm, long days and will not finish from a late-summer sowing outside frost-free zones.
Sunflowers need a long run of warm, long days and will not finish from a late-summer sowing outside frost-free zones.
Fall dates are counted backward from the Zone 7a average first frost, not forward from a sowing date. See the fall planting calendar by zone for the full method.
Spring vs fall sunflowers in Zone 7a
| Planting | Sow or start | In the ground | Harvest |
|---|---|---|---|
| Spring | Apr 17 | Apr 17 | Jul 6 |
| Fall | — | — | — |
Sunflowers in nearby zones
Further reading on sunflowers
- Last frost date and what to plant before it
Why sunflowers can go out before your last frost, and how far before.
- Companion planting chart
What to plant with sunflowers and what to keep away from it.
Other crops in Zone 7a
Frequently asked questions
When should I start sunflowers in Zone 7a?
Direct sow outdoors around Apr 17.
Can I direct sow sunflowers in Zone 7a?
Yes, direct sow around Apr 17.
Can I plant sunflowers in the fall in Zone 7a?
Sunflowers has no useful fall window in Zone 7a. Sunflowers need a long run of warm, long days and will not finish from a late-summer sowing outside frost-free zones.
Will sunflowers survive frost in Zone 7a?
No. Sunflowers is a half-hardy crop and a single light frost ends it, so every Zone 7a planting has to finish before the average first frost.
How many plantings of sunflowers fit in a Zone 7a season?
About 2. Zone 7a averages 198 frost-free days and sunflowers needs roughly 80 days plus a couple of weeks of turnaround, so sowing every 47 days keeps a supply coming.