Plant Basil in Zone 4a

Seed-starting, transplant & harvest dates for USDA Zone 4a

Start indoors

Mar 29

Transplant

May 24

Direct sow

May 24

Harvest (~60d)

Jul 23

Zone 4a averages 135 frost-free days, running from a last spring frost around May 10 to a first fall frost around September 22. Basil needs roughly 60 days from planting out to first harvest, so it uses about 44 percent of that window. Basil is a tender crop, which is what decides where in the window it belongs.

Because basil needs a head start, sow seed indoors around Mar 29, about 6 weeks ahead of the Zone 4a last frost. Transplants go out around May 24. Starting earlier than that in Zone 4a usually backfires: plants outgrow their cells and stall when they finally hit cold soil.

Fall planting: basil in Zone 4a

Basil has no useful fall window in Zone 4a. Basil blackens at the first light frost, so there is no fall window. Move a plant indoors under a light instead.

Basil blackens at the first light frost, so there is no fall window. Move a plant indoors under a light instead.

Fall dates are counted backward from the Zone 4a average first frost, not forward from a sowing date. See the fall planting calendar by zone for the full method.

Spring vs fall basil in Zone 4a

Planting	Sow or start	In the ground	Harvest
Spring	Mar 29	May 24	Jul 23
Fall	—	—	—

Last spring frost

May 10

First fall frost

Sep 22

Growing season

135 days

Basil in nearby zones

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

Other crops in Zone 4a

Tomatoes in Zone 4a Peppers in Zone 4a Cucumbers in Zone 4a Lettuce in Zone 4a Zucchini in Zone 4a Carrots in Zone 4a Beans (bush) in Zone 4a Peas in Zone 4a Broccoli in Zone 4a Spinach in Zone 4a Kale in Zone 4a Onions in Zone 4a Garlic in Zone 4a Potatoes in Zone 4a Squash (winter) in Zone 4a Corn in Zone 4a Radishes in Zone 4a Beets in Zone 4a Eggplant in Zone 4a Cilantro in Zone 4a Parsley in Zone 4a Pumpkins in Zone 4a Sunflowers in Zone 4a

Frequently asked questions

When should I start basil in Zone 4a?

Start basil seeds indoors around Mar 29 (Zone 4a).

Can I direct sow basil in Zone 4a?

Yes, direct sow around May 24.

Can I plant basil in the fall in Zone 4a?