How the windows are calculated
Every window on this page is counted from two anchors: the typical last spring frost and first fall frost for your zone (or your saved city, if you’ve used the frost date lookup). Indoor seed-starting is counted back from the last frost; transplanting and direct sowing are counted forward from it; fall plantings are counted back from the first fall frost so crops mature before cold shuts them down.
seed-start window = last frost − (weeks before) · transplant = last frost + (weeks after)
Cool-season vs. warm-season crops
The single most useful division in vegetable gardening: cool-season crops (peas, lettuce, brassicas, roots) germinate in cold soil, tolerate frost, and fade in summer heat — plant them before the last frost and again in late summer. Warm-season crops (tomatoes, peppers, squash, melons, corn, beans) are killed by frost and stall in cold soil — they wait until after it. The calendar encodes this per crop, so the windows already reflect which side of the line each crop sits on.
Zone dates are the starting point, not gospel
Zones describe winter cold, so frost timing within a zone varies with elevation, latitude, and distance to water. Use the zone calendar to plan the season’s shape, then tighten it with your local frost dates. For a printable master schedule of everything on your seed rack, use the seed starting scheduler, and browse crop-by-crop guides for depth on any single crop.
Frequently asked questions
Should I use my zone or my frost dates for planting timing?
Frost dates, when you have them. Hardiness zones describe winter minimum temperatures, not frost timing — two zone-7 gardens can have last frosts weeks apart. This calendar uses typical frost dates for each zone as a solid default, but the ZIP-level lookup is more precise.
What does "start seeds indoors 6–8 weeks before last frost" actually mean?
Count back from your average last spring frost date on a calendar. If your last frost is May 1, an "8–6 weeks before" crop gets sown indoors between March 6 and March 20. The windows here do that counting for you.
Why do some crops have no indoor-start date?
Root crops (carrots, beets), beans, peas, corn, and a few herbs like dill resent transplanting — their roots don’t recover from the move. They’re direct-sown in the garden, so only a direct-sow window applies.
Can I really plant before my last frost date?
Yes — hardy and half-hardy crops are built for it. Peas, spinach, kale, onions, and potatoes all go in 2–6 weeks before the last frost and take light freezes in stride. Only tender crops (tomatoes, peppers, squash, basil) must wait until after it.