Here is a list of the major vegetables and the “best” time to plant:
Cabbage
Indoor growing time prior to transplanting: 5 to 6 weeks
Germination time: 10-12 days
Seed planting depth: 1/2 inch
Temperature range for optimal germination: 70-80°F
Optimal growing temperatures day: 60-70°F night: 50-60°F
Outdoor plant spacing: 12-18 inch
Days to maturity: 60-110
Cool-Season or Warm-Season Crop: Cool-season
Suited for plastic mulch and drip irrigation: No
When to plant outdoors: 4 weeks before last frost
Harvesting characteristics: When heads are solid but not yet cracking
Cauliflower
Indoor growing time prior to transplanting: 5 to 6 weeks
Germination time: 10-21 days
Seed planting depth: 1/4 to 1/2 inch
Temperature range for optimal germination: 70-80°F
Optimal growing temperatures** day: 60-70°F night: 55-60°F
Outdoor plant spacing: 18 inch
Days to maturity: 50-72
Cool-Season or Warm-Season Crop: Cool-season
Suited for plastic mulch and drip irrigation: No
When to plant outdoors: 4 weeks before last frost
Harvesting characteristics: when head is compact but before curd opens and becomes “ricey”
Broccoli
Indoor growing time prior to transplanting: 5 to 6 weeks
Germination time: 10-14 days
Seed planting depth: 1/4 to 1/2 inch
Temperature range for optimal germination: 70-80°F
Optimal growing temperatures day: 60-70°F night: 50-60°F
Outdoor plant spacing: 18-24 inch
Days to maturity: 50-72
Cool-Season or Warm-Season Crop: Cool-season
Suited for plastic mulch and drip irrigation: No
When to plant outdoors: 4 weeks before last frost
Harvesting characteristics: when buds are tight and head is compact
Brussels Sprouts
Indoor growing time prior to transplanting: 5 to 6 weeks
Germination time: 7-14 days
Seed planting depth: 1/4 to 1/2 inch
Temperature range for optimal germination: 70-80°F
Optimal growing temperatures day: 60-70°F night: 50-60°F
Outdoor plant spacing: 18-24 inch
Days to maturity: 90-120
Cool-Season or Warm-Season Crop: Cool-season
Suited for plastic mulch and drip irrigation: No
When to plant outdoors: 5 weeks after last frost
Harvesting characteristics: when plump, firm and glossy
Head Lettuce
Indoor growing time prior to transplanting: 5 to 7 weeks
Germination time: 7-10 days
Seed planting depth: 1/8 inch
Temperature range for optimal germination: 65-75°F
Optimal growing temperatures day: 60-70°F night: 60-70°F
Outdoor plant spacing: 12 inch
Days to maturity: 40-90
Cool-Season or Warm-Season Crop: Cool-season
Suited for plastic mulch and drip irrigation: No
When to plant outdoors: 1-2 weeks before last frost
Harvesting characteristics: when heads are firm and glossy
Onions
Indoor growing time prior to transplanting: 9 to 11 weeks
Germination time: 10-15 days
Seed planting depth: 3/8 inch
Temperature range for optimal germination: 65-80°F
Optimal growing temperatures day: 60-70°F night: 45-55°F
Outdoor plant spacing: 12 inch
Days to maturity: 60-115
Cool-Season or Warm-Season Crop: Cool-season
Suited for plastic mulch and drip irrigation: yes
When to plant outdoors: 4 weeks before last frost
Harvesting characteristics: Green or bunching onion – when desired; bulb onion – when above-ground leaves fall, allow to cure 1 – 2 days, thinnings can be used anytime.
Celery
Indoor growing time prior to transplanting: 10 to 12 weeks
Germination time: 21 days
Seed planting depth: 1/8 inch
Temperature range for optimal germination: 60-70°F
Optimal growing temperatures day: 65-75°F night: 55-65°F
Outdoor plant spacing: 9-12 inch
Days to maturity: 110-120
Cool-Season or Warm-Season Crop: Cool/warm-season
Suited for plastic mulch and drip irrigation: yes
When to plant outdoors: after last frost
Harvesting characteristics: When outer petioles can be pulled anytime for immediate use, fully mature when about 3 inches by 21 inches.
Tomatoes
Indoor growing time prior to transplanting: 5 to 7 weeks
Germination time: 7-10 days
Seed planting depth: 1/4 to 1/2 inch
Temperature range for optimal germination: 70-80°F
Optimal growing temperatures day: 70-80°F night: 60-65°F
Outdoor plant spacing: 18-24 inch
Days to maturity: 52-90
Cool-Season or Warm-Season Crop: Warm-season
Suited for plastic mulch and drip irrigation: Yes
When to plant outdoors: After last frost
Harvesting characteristics: Harvesting characteristics: when evenly colored and firm
Peppers
Indoor growing time prior to transplanting: 6 to 8 weeks
Germination time: 10-12 days
Seed planting depth: 1/4 to 1/2 inch
Temperature range for optimal germination: 75-85°F
Optimal growing temperatures day: 70-80°F night: 60-70°F
Outdoor plant spacing: 18-24 inch
Days to maturity: 55-80
Cool-Season or Warm-Season Crop: Warm-season
Suited for plastic mulch and drip irrigation: Yes
When to plant outdoors: After last frost
Harvesting characteristics: When glossy in color and firm, either ‘green’ mature or final color maturity for the type and maturity.
Eggplant
Indoor growing time prior to transplanting: 7 to 9 weeks
Germination time: 10-12 days
Seed planting depth: 1/4 to 1/2 inch
Temperature range for optimal germination: 75-90°F
Optimal growing temperatures day: 70-80°F night: 65-70°F
Outdoor plant spacing: 24 inch
Days to maturity: 50-75
Cool-Season or Warm-Season Crop: Warm-season
Suited for plastic mulch and drip irrigation: Yes
When to plant outdoors: when night temperatures are above 50°F
Harvesting characteristics: When glossy in color and of satisfactory size for the cultivar and before seeds mature and darken.
Cucumber
Indoor growing time prior to transplanting: 3 to 4 weeks
Germination time*: 7-8 days
Seed planting depth: 3/4 to 1 inch
Temperature range for optimal germination: 75-95°F
Optimal growing temperatures day: 70-90°F night: 60-70°F
Outdoor plant spacing: 12 inch
Days to maturity: 48-70
Cool-Season or Warm-Season Crop: Warm-season
Suited for plastic mulch and drip irrigation: Yes
When to plant outdoors: 1 week after last frost
Harvesting characteristics: When 3 – 4 inches long for pickling, 6-10 inches for slicing and fully green, yellow fruit should be discarded.
Muskmelon
Indoor growing time prior to transplanting: 3 to 4 weeks
Germination time: 7 days
Seed planting depth: 3/4 to 1 inch
Temperature range for optimal germination: 75-95°F
Optimal growing temperatures day: 70-90°F night: 60-70°F
Outdoor plant spacing: 12 inch
Days to maturity: 68-95
Cool-Season or Warm-Season Crop: Warm-season
Suited for plastic mulch and drip irrigation: Yes
When to plant outdoors: 1 week after last frost
Harvesting characteristics: When melon begins to detach from stem
Watermelon
Indoor growing time prior to transplanting: 3 to 4 weeks
Germination time: 6-8 days
Seed planting depth: 3/4 to 1 inch
Temperature range for optimal germination: 75-95°F
Optimal growing temperatures day: 70-90°F night: 60-70°F
Outdoor plant spacing: 18 inch
Days to maturity: 68-95
Cool-Season or Warm-Season Crop: Warm-season
Suited for plastic mulch and drip irrigation: Yes
When to plant outdoors: 1 week after last frost
Harvesting characteristics: When tendril nearest stem attachment turns brown and shrivels
Summer Squash
Indoor growing time prior to transplanting: 3 to 4 weeks
Germination time: 7-10 days
Seed planting depth: 3/4 to 1 inch
Temperature range for optimal germination: 75-95°F
Optimal growing temperatures day: 70-90°F night: 60-70°F
Outdoor plant spacing: 18 inch
Days to maturity: 42-65
Cool-Season or Warm-Season Crop: Warm-season
Suited for plastic mulch and drip irrigation: Yes
When to plant outdoors: 1 week after last frost
Harvesting characteristics: Zucchini, yellow and other elongate types when 5 to 8 inches long and skin is tender, skin must be very tender on patty pan and round types and be 2 to 4 inches in diameter.
Sources
Holcomb, E.J. (Ed). 1994. Bedding Plants IV 4th edition. Pennsylvania Flower Growers, Ball Publishing. Batavia, Il.
Maynard, D.N., and Hochmuth, G. 1997. Knott’s Handbook for Vegetable Growers, 4th edition. John Wiles & Sons. New York, NY.
Nardozzi, C. 1999. Vegetable Gardening for Dummies. IDG Books Worldwide, Inc., Foster City, CA.
Phillips, R. and Rix, M. 1993. The Random House Book of Vegetables. Random House Publishers. New York, NY.
Reilly, A. 1990. Taylor’s Pocket Guide to Vegetables, Chanticleer Press Edition. Houghton Mifflin Company. Boston, MA.
Prepared by Elsa Sánchez, associate professor of horticulture and Pete Ferretti, retired professor of vegetable crops.
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