Cool Season: broccoli, cabbage, and cauliflower | Warm Season: tomato, pepper, squash and melons | |
Germination | 40°F to 90°F 80°F optimum | 50°F to 100°F 80°F optimum |
Growth | Daytime 65F° - 80°F preferred 40°F minimum Nighttime greater than 32°F for tender transplants down to mid-20s°F for established plants | Daytime 86°F optimum 60°F minimum Week below 55°F will stunt plant, reducing yields. Nighttime above 32°F |
Flowering | Temperature extremes lead to bolting and buttoning. | Nighttime: Below 55°F, non- viable pollen (use blossom set hormones). Daytime: Greater than 95°F by 10 a.m., blossoms abort |
Soil | Cool Use organic mulch to cool soil. Since seeds germinate best in warm soils, use transplants for spring planting, and direct seeding for mid-summer plantings (fall harvest). | Warm Use black plastic mulch to warm soil, increasing yields and |
Vegetable | Germination Temperature minimum |
Germination Temperature optimum |
Germination Temperature maximum |
Plant Spacing 2 | Planting Depth | Days to Germination | Typical Days to Harvest | Age of Transplants (weeks) |
Cool Season Crops |
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Beets | 40° | 80° | 90° | 4-6” | ¾-1” | 10-Jul | 60 | |
Broccoli | 40° | 80° | 90° | 18” | ½” | 10-Mar | 65T | 5-7 a |
Cabbage | 40° | 80° | 90° | 18” | ½” | 10-Mar | 85T | 5-7 a |
Carrots | 40° | 80° | 90° | 2-3” | ¼” | 17-Oct | 70 | |
Cauliflower | 40° | 80° | 90° | 18” | ½” | 10-Mar | 65T | 5-7 a |
Kohlrabi | 40° | 80° | 90° | 7-9” | ½” | 10-Mar | 50 | |
Leeks | 40° | 80° | 90° | 4-6” | ¼” | 12-Jul | 120 | |
Lettuce (leaf types) | 35° | 70° | 70° | 7-9” | ¼” | 10-Apr | 60 | |
Onion, green | 35° | 80° | 90° | 2-3” | ¼” | 12-Jul | 60 | |
Onions, dry (seed) | 35° | 80° | 90° | 4-6” | ¼” | 12-Jul | 110 | |
Onions, dry (sets) | 4-6” | 1-2” | ||||||
Parsnips | 35° | 70° | 90° | 5-6” | ½” | 15-25 | 70 | |
Peas | 40° | 70° | 80° | 4-6”or 3” x 8” | 1” | 15-Jun | 65 | |
Potatoes | 45° | 12-15” | 4-6” | 125 | ||||
Radish | 40° | 80° | 90° | 2-3” | ½” | 10-Mar | 30 | |
Spinach | 40° | 70° | 70° | 4-6” | ½” | 14-Jun | 40 | |
Swiss Chard | 40° | 85° | 95° | 7-9” | 1” | 10-Jul | 60 | |
Turnips | 40° | 80° | 100° | 4-6” | ½” | 10-Mar | 50 | |
Warm Season Crops |
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Beans | 50° | 80° | 90° | 6” or 4” x 12” | 1-1½” | 14-Jun | 60 | |
Cantaloupe | 60° | 90° | 100° | 36-48” | 1-1½” | 12-Mar | 85 | 2-3 b |
Corn | 50° | 80° | 100° | 12” x 30” or 9” x 36" | 1-1½” | 10-May | 60-90 | |
Cucumbers | 60° | 90° | 100° | 6” trellised 24-36” untrellised | 1” | 10-Jun | 55 | 2-3 b |
Eggplant | 60° | 80° | 90° | 18-24” | ¼” | 14-Jul | 60T | 6-9 c |
Pepper | 60° | 80° | 90° | 15-18” | ¼” | 20-Oct | 70T | 6-8 c |
Tomato | 50° | 80° | 100° | trellised: 24” between plants | ¼” | 14-Jun | 65T | 5-7 c |
Squash, Summer | 60° | 90° | 100° | 36-48” | 1-1½” | 12-Mar | 50 | 2-3 d |
Squash, Winter | 60° | 90° | 100° | 36-48” | 1-1½” | 10-Jun | 100 | 2-3 d |
Watermelons | 60° | 90° | 110° | 36-48” | 1-1½” | 12-Mar | 85 | 2-3 d |