Here is a chart that shows preferred soil and air temperature for most vegetables, how many weeks early you need to start seeds and also what sign of the zodiac is best to plant in. With this information you can start seeds under lights and have them ready to go in when the weather warms up.* In mild winter areas the hardy crops can be planted about a month later and held over winter.

Vegetable
Crop

Start Weeks Before Spring Set out Date

Set Out Weeks Before Frost Date

Set Out Weeks After Frost Date

Minimum Soil Temp.

Preferred Air Temp.

Length of Season in days

Start Weeks Before Fall Frost Date*

Zodiac Signs

Frost Tolerance

Broccoli

4-6

4

2-3

40 F

60 F

55-85

15

Can, Sc, P, L

hardy

Cabbage

4-6

5

2-3

20 F

60 F

60-110

15

Can, Sc, P, L, T

hardy

Collards

4-6

4

2

40 F

60-65 F

70-80

15

Can, Sc, P

hardy

Kale

4-6

5

2

40 F

60-65 F

65-75

15

Can, Sc, P

hardy

Leeks

4-6

5

2

65-75 F

55-75 F

85-150

15

Can, Sag, P

hardy

Onion (seed)

4-6

6

2

40 F

55-75 F

92-130

20

L,T,P,Can, Sag

hardy

Peas

n/a

4

2-3

40-55 F

60-65 F

55-75

16

Can, Sc, P, T

hardy

Spinach

4-6

3-6

4

40 F

35-75 F

60-65

8

Can, Sc, P

hardy

Turnips

4

4

2

50 F

60-65 F

35-50

13

Can, Sc, P, T, Cap, L

hardy

Beets

n/a

4

2-4

40 F

60-65 F

55-80

14

Can, Sc, P, Cap, L

half-hardy

Carrots

n/a

4

2-4

45-85 F

60-65 F

60-80

15

T,Can, Sc, P, L

half-hardy

Cauliflower

2-4

4

2

60 F

60-65 F

55-110

15

Can, Sc, P, L

half-hardy

Celery

2-4

4

2

60 F

60-65 F

90-140

 

Can, Sc, P

half-hardy

Lettuce

2-6

2

3

40 F

60-65 F

45-100

13

Can, Sc, P, L, T

half-hardy

Mustard

2-4

5

2

45 F

60-65 F

30-50

15

Can, Sc, P

half-hardy

Parsnips

2-4

4

3-4

50 F

40-70 F

80-120

15

T,Cap,Can, Sc

half-hardy

Potatoes

n/a

2-4

2-4

40 F

60-65 F

100-115

16

Can, Sc, P, T,Cap

half-hardy

Radishes

2-4

4-6

2-4

40 F

60-65 F

25-50

8

Can, L,T,Sc, P, Cap

half-hardy

Swiss Chard

2-4

3-4

4

50 F

40-85 F

50-60

15

Can, Sc, P

half-hardy

Beans, snap

n/a

n/a

1-2

60 F

70-80 F

40-55

15

Can, Sc, P, T, L

tender

Beans, runner

n/a

n/a

1-2

60 F

70-80 F

65-85

15

Can, Sc, P, T, L

tender

Beans, shelling

n/a

n/a

1-2

60 F

70-80 F

85-115

15

Can, P

tender

Corn

n/a

n/a

2-3

60 F

60-75 F

70-100

16

Can, Sc, P

tender

Okra

n/a

n/a

3-4

60 F

70-85 F

50-60

16

Can, Sc, P, L

tender

Tomatoes

6-10

n/a

4

60 F

70-85 F

65-85

15

Sc,Can, P, L

tender

Cucumber

2-3

1

2

60 F

65-85 F

50-75

16

Can, Sc, P

very tender

Eggplant

8-10

n/a

2-3

65 F

70-85 F

65-80

15

Can, Sc, P, L

very tender

Luffa

4-6

n/a

2-4

70-95 F

65-75 F

120

18

Can, Sc, P

very tender

Melon

2-4

n/a

2-3

50 F

80-100 F

80-125

16

Can, Sc, P

very tender

Peanuts

n/a

n/a

2

60 F

65-85 F

120

 16

Can, Sc, P, Cap

very tender

Peppers

6-8

n/a

2-3

60 F

55-90 F

60-80

16

Can, Sc, P

very tender

Pumpkins

3

n/a

2-3

40 F

65-75 F

90-120

16

Can, Sc, P, L

very tender

Squash, summer

4

n/a

3-4

60 F

65-75 F

45-75

16

Can, Sc, P, L

very tender

Squash, winter

4

n/a

3-4

60 F

65-75 F

70-120

18

Can, Sc, P,L

very tender

Sweet Potatoes

6-8

n/a

2-3

65 F

70-85 F

150-170

18

Can, Sc, P, T,Cap

very tender