Plant Sunflowers in Zone 6b

Seed-starting, transplant & harvest dates for USDA Zone 6b

Direct sow

Apr 22

Harvest (~80d)

Jul 11

Zone 6b averages 186 frost-free days, running from a last spring frost around April 15 to a first fall frost around October 18. Sunflowers needs roughly 80 days from planting out to first harvest, so it uses about 43 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 22, after the Zone 6b last frost has passed and the soil has warmed.

Fall planting: sunflowers in Zone 6b

Sunflowers has no useful fall window in Zone 6b. 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 6b 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 6b

Planting	Sow or start	In the ground	Harvest
Spring	Apr 22	Apr 22	Jul 11
Fall	—	—	—

Last spring frost

Apr 15

First fall frost

Oct 18

Growing season

186 days

Sunflowers in nearby zones

Sunflowers in Zone 6a (colder) Sunflowers in Zone 7a (warmer) Full Sunflowers grow guide Zone 6b planting calendar

Other crops in Zone 6b

Tomatoes in Zone 6b Peppers in Zone 6b Cucumbers in Zone 6b Lettuce in Zone 6b Zucchini in Zone 6b Carrots in Zone 6b Beans (bush) in Zone 6b Peas in Zone 6b Broccoli in Zone 6b Spinach in Zone 6b Kale in Zone 6b Onions in Zone 6b Garlic in Zone 6b Potatoes in Zone 6b Squash (winter) in Zone 6b Corn in Zone 6b Radishes in Zone 6b Beets in Zone 6b Eggplant in Zone 6b Basil in Zone 6b Cilantro in Zone 6b Parsley in Zone 6b Pumpkins in Zone 6b

Frequently asked questions

When should I start sunflowers in Zone 6b?

Direct sow outdoors around Apr 22.

Can I direct sow sunflowers in Zone 6b?

Yes, direct sow around Apr 22.

Can I plant sunflowers in the fall in Zone 6b?