Plant Sunflowers in Zone 8b

Seed-starting, transplant & harvest dates for USDA Zone 8b

Direct sow

Mar 22

Harvest (~80d)

Jun 10

Zone 8b averages 245 frost-free days, running from a last spring frost around March 15 to a first fall frost around November 15. Sunflowers needs roughly 80 days from planting out to first harvest, so it uses about 33 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 Mar 22, after the Zone 8b last frost has passed and the soil has warmed. At 80 days to harvest, a 245-day Zone 8b season has room for about 2 sowings, so stagger them rather than planting everything at once.

Fall planting: sunflowers in Zone 8b

Sunflowers has no useful fall window in Zone 8b. 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 8b 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 8b

Planting	Sow or start	In the ground	Harvest
Spring	Mar 22	Mar 22	Jun 10
Fall	—	—	—

Last spring frost

Mar 15

First fall frost

Nov 15

Growing season

245 days

Sunflowers in nearby zones

Sunflowers in Zone 8a (colder) Sunflowers in Zone 9a (warmer) Full Sunflowers grow guide Zone 8b planting calendar

Other crops in Zone 8b

Tomatoes in Zone 8b Peppers in Zone 8b Cucumbers in Zone 8b Lettuce in Zone 8b Zucchini in Zone 8b Carrots in Zone 8b Beans (bush) in Zone 8b Peas in Zone 8b Broccoli in Zone 8b Spinach in Zone 8b Kale in Zone 8b Onions in Zone 8b Garlic in Zone 8b Potatoes in Zone 8b Squash (winter) in Zone 8b Corn in Zone 8b Radishes in Zone 8b Beets in Zone 8b Eggplant in Zone 8b Basil in Zone 8b Cilantro in Zone 8b Parsley in Zone 8b Pumpkins in Zone 8b

Frequently asked questions

When should I start sunflowers in Zone 8b?

Direct sow outdoors around Mar 22.

Can I direct sow sunflowers in Zone 8b?

Yes, direct sow around Mar 22.

Can I plant sunflowers in the fall in Zone 8b?

Sunflowers has no useful fall window in Zone 8b. 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 8b?

No. Sunflowers is a half-hardy crop and a single light frost ends it, so every Zone 8b planting has to finish before the average first frost.

How many plantings of sunflowers fit in a Zone 8b season?

About 2. Zone 8b averages 245 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.