Frost & Furrow

Planting guides

When to start seeds for 15 common vegetables and herbs, and planting calendars for USDA zones 3 to 10. Every guide cites university extension sources and links to a calculator prefilled for that crop.

When to start seeds, by crop

TomatoesIndoors 6–8 weeks before setting out; plant out 1–2 weeks after last frost.PeppersIndoors 8–10 weeks before setting out; plant out about 2 weeks after last frost.EggplantIndoors 8–10 weeks before setting out; plant out 2–3 weeks after last frost.BroccoliIndoors 4–6 weeks before setting out; plant out 2–4 weeks before last frost.CabbageIndoors 4–6 weeks before setting out; plant out about 4 weeks before last frost.CauliflowerIndoors 4–6 weeks before setting out; plant out about 2 weeks before last frost.LettuceIndoors 4–5 weeks before setting out; plant out 3–4 weeks before last frost, or direct sow.KaleIndoors 4–6 weeks before setting out; plant out about 4 weeks before last frost, or direct sow.OnionsIndoors 8–10 weeks before setting out; plant out about 4 weeks before last frost.CucumbersDirect sow when soil reaches 70°F, or start indoors 3–4 weeks ahead in pots.Squash and zucchiniDirect sow after last frost at 70°F soil; or start 3–4 weeks ahead, out 2 weeks after frost.MelonsIndoors 3–4 weeks ahead in 4-inch pots; plant out 2 weeks after last frost, soil 65°F+.BasilIndoors 6–8 weeks ahead (some guides say 3–6); plant out 2 weeks after last frost.Herbs (parsley, cilantro, dill, chives)Parsley indoors 9–10 weeks ahead; dill and cilantro direct sown; chives from divisions.SpinachDirect sow as soon as soil is workable; or start indoors 4–6 weeks ahead, out 3–6 weeks before frost.

Planting calendars by USDA zone

Hardiness zones describe winter cold, not spring frost, so each zone page shows a range of real frost dates from NOAA climate normals and a month-by-month table you can adjust to your own date.

Zone 3Median last frost May 13 – May 29 at example stations.Zone 4Median last frost May 7 – May 21 at example stations.Zone 5Median last frost Apr 18 – May 26 at example stations.Zone 6Median last frost Apr 13 – May 5 at example stations.Zone 7Median last frost Mar 26 – Apr 24 at example stations.Zone 8Median last frost Mar 8 – Apr 6 at example stations.Zone 9Median last frost Jan 14 – Mar 13 at example stations.Zone 10Median last frost Jan 5 – Jan 25 at example stations.

Tools these guides use

Seed starting calculatorDates for 33 crops from your last frost.Fall planting calculatorLatest sowing date before first frost.How to find your frost datesNOAA normals, extension services and your own records.

How these guides are written

Each guide pulls its numbers from published extension sources: the University of New Hampshire Extension planting table for weeks indoors and set-out timing, J. F. Harrington's germination data (published by Oregon State University Extension) and Iowa State University Extension for germination temperatures and days, and crop-specific guides from the University of Minnesota and other extension services for transplanting and growing details. Where sources disagree, the guide says so and gives both figures. Sources are listed at the bottom of every page.