Planting by Zone
A planting calendar fitted to your real frost dates and season length, computed from the 30-year NOAA record at your nearest U.S. weather station.
The rule of thumb, by season length
| Season length | Strategy | Good crops |
|---|---|---|
| Under 90 days | Almost everything from transplants; use cold frames or row cover | Peas, lettuce, kale, radishes, beets, spinach, broccoli |
| 90 to 140 days | Start warm crops indoors; direct sow cool crops | Tomatoes, peppers, beans, squash, cucumbers |
| 140 to 200 days | Direct sow most crops; succession plant for steady harvest | All of the above plus melons, eggplant, sweet potatoes |
| Over 200 days / no freeze | Plant around heat and rainfall, not frost | Year-round greens, citrus where hardy, tropical crops |
Count back from last frost
Cool-season crops can go in as soon as the soil can be worked, often four to six weeks before the last frost. Warm-season crops wait until after it. The planting calendar above uses your actual NOAA last frost date so the windows are tuned to your station, not a zone average.
Questions, answered plainly
Should I use hardiness zones or frost dates?
Both, for different jobs. USDA hardiness zones tell you which perennials, shrubs, and trees survive your winters. Frost dates tell you when to sow and transplant annual vegetables and flowers. A planting calendar runs on frost dates and season length, which is what this tool computes.
When can I plant tomatoes outside?
Start seeds indoors about six weeks before your last frost date and transplant a week or two after it, once nights hold above 50 F. In Denver that means indoor starts in mid March and transplanting in mid May; in Boston, indoor starts in early April and transplanting in late May. Set your place above for your exact dates.
My frost-free season is short. What still works?
Plenty. Peas, lettuce, spinach, kale, radishes, beets, and carrots tolerate frost on one or both ends of the season. For warm crops in a short season, choose short-maturity varieties, start indoors, and use transplants.