Plant Zucchini in Zone 3b

Seed-starting, transplant & harvest dates for USDA Zone 3b

Start indoors

Apr 22

Transplant

May 27

Direct sow

May 27

Harvest (~55d)

Jul 21

Zone 3b averages 128 frost-free days, running from a last spring frost around May 13 to a first fall frost around September 18. Zucchini needs roughly 55 days from planting out to first harvest, so it uses about 43 percent of that window. Zucchini is a tender crop, which is what decides where in the window it belongs.

Because zucchini needs a head start, sow seed indoors around Apr 22, about 3 weeks ahead of the Zone 3b last frost. Transplants go out around May 27. Starting earlier than that in Zone 3b usually backfires: plants outgrow their cells and stall when they finally hit cold soil.

Fall planting: zucchini in Zone 3b

Zucchini has no useful fall window in Zone 3b. One midsummer sowing of zucchini replaces the spring plants right as squash vine borer takes them out.

One midsummer sowing of zucchini replaces the spring plants right as squash vine borer takes them out.

Fall dates are counted backward from the Zone 3b average first frost, not forward from a sowing date. See the fall planting calendar by zone for the full method.

Spring vs fall zucchini in Zone 3b

Planting	Sow or start	In the ground	Harvest
Spring	Apr 22	May 27	Jul 21
Fall	—	—	—

Last spring frost

May 13

First fall frost

Sep 18

Growing season

128 days

Zucchini in nearby zones

Zucchini in Zone 3a (colder) Zucchini in Zone 4a (warmer) Full Zucchini grow guide Zone 3b planting calendar

Other crops in Zone 3b

Tomatoes in Zone 3b Peppers in Zone 3b Cucumbers in Zone 3b Lettuce in Zone 3b Carrots in Zone 3b Beans (bush) in Zone 3b Peas in Zone 3b Broccoli in Zone 3b Spinach in Zone 3b Kale in Zone 3b Onions in Zone 3b Garlic in Zone 3b Potatoes in Zone 3b Squash (winter) in Zone 3b Corn in Zone 3b Radishes in Zone 3b Beets in Zone 3b Eggplant in Zone 3b Basil in Zone 3b Cilantro in Zone 3b Parsley in Zone 3b Pumpkins in Zone 3b Sunflowers in Zone 3b

Frequently asked questions

When should I start zucchini in Zone 3b?

Start zucchini seeds indoors around Apr 22 (Zone 3b).

Can I direct sow zucchini in Zone 3b?

Yes, direct sow around May 27.

Can I plant zucchini in the fall in Zone 3b?