Plant Sunflowers in Zone 5a

Seed-starting, transplant & harvest dates for USDA Zone 5a

Direct sow

May 7

Harvest (~80d)

Jul 26

Zone 5a averages 156 frost-free days, running from a last spring frost around April 30 to a first fall frost around October 3. Sunflowers needs roughly 80 days from planting out to first harvest, so it uses about 51 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 May 7, after the Zone 5a last frost has passed and the soil has warmed.

Fall planting: sunflowers in Zone 5a

Sunflowers has no useful fall window in Zone 5a. 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 5a 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 5a

Planting	Sow or start	In the ground	Harvest
Spring	May 7	May 7	Jul 26
Fall	—	—	—

Last spring frost

Apr 30

First fall frost

Oct 3

Growing season

156 days

Sunflowers in nearby zones

Sunflowers in Zone 4b (colder) Sunflowers in Zone 5b (warmer) Full Sunflowers grow guide Zone 5a planting calendar

Other crops in Zone 5a

Tomatoes in Zone 5a Peppers in Zone 5a Cucumbers in Zone 5a Lettuce in Zone 5a Zucchini in Zone 5a Carrots in Zone 5a Beans (bush) in Zone 5a Peas in Zone 5a Broccoli in Zone 5a Spinach in Zone 5a Kale in Zone 5a Onions in Zone 5a Garlic in Zone 5a Potatoes in Zone 5a Squash (winter) in Zone 5a Corn in Zone 5a Radishes in Zone 5a Beets in Zone 5a Eggplant in Zone 5a Basil in Zone 5a Cilantro in Zone 5a Parsley in Zone 5a Pumpkins in Zone 5a

Frequently asked questions

When should I start sunflowers in Zone 5a?

Direct sow outdoors around May 7.

Can I direct sow sunflowers in Zone 5a?

Yes, direct sow around May 7.

Can I plant sunflowers in the fall in Zone 5a?