Planting Calendar by USDA Zone
Timing is half of gardening: the same tomato seedling thrives planted after the last frost and dies planted two weeks too early. Your USDA zone and frost dates turn guesswork into a calendar — here’s how to build yours.
Find your USDA zone and your average last spring frost date, then count backwards: start tomatoes and peppers indoors 6–8 weeks before it, direct-sow peas, radishes, and spinach 2–4 weeks before it, and set out warm-season crops only after all frost danger has passed.
Find your USDA zone
The USDA Plant Hardiness Zone Map divides North America by average annual minimum winter temperature, from Zone 1 (coldest) to Zone 13 (warmest). Most US gardeners fall in Zones 3–10. Your zone tells you which perennials survive your winter — but for timing vegetable sowings, the number that matters most is your average last spring frost date, which tracks roughly with zone.
Frost dates by zone
These are broad averages — always confirm with your county extension service or a local almanac, since elevation and large lakes shift dates by weeks:
| USDA zone | Avg. last spring frost | Avg. first autumn frost |
|---|---|---|
| Zone 3 | Mid-May | Mid-September |
| Zone 4 | Early May | Late September |
| Zone 5 | Late April | Early October |
| Zone 6 | Mid-April | Mid-October |
| Zone 7 | Early April | Late October |
| Zone 8 | Mid-March | Mid-November |
| Zone 9 | Late February | Early December |
| Zone 10 | Frost rare | Frost rare |
Timing by crop
Seed packets speak in weeks relative to your last frost date (LFD). Cool-season crops shrug off light frost; warm-season crops die in it:
| Crop | When (relative to last frost) | How |
|---|---|---|
| Peas | 4–2 weeks before | Direct sow |
| Radishes, spinach | 4–2 weeks before | Direct sow |
| Carrots, beets | 3–1 weeks before | Direct sow |
| Lettuce | 3–1 weeks before | Direct sow or transplant |
| Brassica transplants | 2–0 weeks before | Transplant hardened seedlings |
| Tomatoes, peppers | Start indoors 8–6 weeks before; transplant 0–2 weeks after | Indoors, then transplant |
| Beans, corn, squash, cucumbers | 1–3 weeks after | Direct sow into warm soil |
The count-back formula
Indoor sow date = last frost date − weeks listed on the packetExample: your last frost averages 15 April and the tomato packet says “start indoors 6 weeks before last frost.” Count back six weeks → sow around 4 March. Keep seedlings under strong light and don’t rush them outside: transplant when nights stay reliably above 50°F.
Succession sowing and autumn crops
Don’t stop in spring. Sow fast crops (radishes, lettuce, bush beans) every 2–3 weeks for continuous harvests, and plan autumn crops by counting back from your first autumn frost: sow date = first frost − (days to maturity + 14 days for slowing autumn growth). A Zone 6 gardener with a mid-October first frost sows 60-day carrots around mid-July for an autumn harvest.
Get your exact sowing dates
Done with the averages? Plug in your real last frost date and let the Seed Starting Calendar Generator count back every crop for you.
Frequently asked questions
How do I find my exact last frost date?
Your county extension service publishes local frost dates, and most almanacs list them by town. The zone table above is a starting average — your town’s real date can differ by two weeks or more, so look it up once and write it down.
Does my zone affect summer growing too?
Only indirectly. USDA zones measure winter cold, not summer heat — a Zone 5 garden can still hit 95°F in July. For heat-loving crops, your frost-free growing season length (last spring frost to first autumn frost) matters more than the zone number.
Can I plant before the last frost date?
Cool-season crops, yes: peas, spinach, radishes, and carrots tolerate light frosts, and fleece adds a few degrees of protection. Warm-season crops — tomatoes, peppers, beans, squash — wait until all frost danger has passed and the soil has warmed.
What about autumn planting?
Count backwards from your first autumn frost: subtract the crop’s days to maturity plus about two extra weeks for slower autumn growth. Sow too late and the crop stalls in the cold; the formula above keeps you on time.
Do microclimates change my dates?
Yes. Walled gardens, urban plots, and south-facing slopes run warmer — shift dates about a week earlier in spring. Low-lying spots collect cold air and frost first — shift a week later. Observe your own garden for a season and adjust.
Related guides
Easiest Vegetables to Grow for Beginners
Know when to sow? Pick forgiving crops to start with.
How to Grow Tomatoes in a Raised Bed
Warm-season timing matters most for tomatoes.
Square Foot Gardening: Spacing for Small Beds
Timing set? Plan what fits in each square foot.