Sunflower in Zone 8a & 8b
Helianthus annuus
When to plant sunflower in zone 8b
Zones 8a and 8b share the same average frost dates in our data, so this page covers both.
Method: Direct sow: Direct-sow outside. Sunflower doesn't transplant well, or doesn't need the extra time indoors.
| Start indoors | Not typically started indoors |
|---|---|
| Direct sow / transplant outside | Mar 25–Apr 1 |
| Estimated bloom | Jun 13–Jun 20 (~80 days after direct-sowing) |
Spacing: about 2 square feet per plant (square-foot-gardening spacing). Mature height: 3-12 ft.

Sunflowers are one of the few flowers in a vegetable garden that does actual structural work: a single or branching stalk anywhere from 3 to 12-plus feet tall, topped with big daisy-form heads (yellow petals ringing a dark brown center, though some varieties run red or bronze), can serve as a living trellis for pole beans or climbing cucumbers, instead of building one out of stakes and twine.
How sunflower fits zone 8's season
Zone 8b's frost-free window runs about 230 days, from March 25 to November 10. Sunflower needs about 80 days from sowing to first harvest.
Good companions
- Bush Beans: Sturdy stalk can serve as a living trellis for pole beans once well established.
- Cucumber: Sturdy stalk can serve as a living trellis for climbing cucumbers.
Where to buy sunflower seeds
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing sunflower" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 8b calendar · Full companion planting guide · Full plant profile · Plan your beds in the Garden Designer →

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Growing Sunflower in USDA zone 8b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
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