Typical tomato planting dates by zone
These are the median last frost dates across ZIP codes in each zone (NOAA 1991 to 2020 normals). Your own date depends on where you are in the zone, so look up your ZIP code.
| Zone | Typical last frost | Plant tomatoes from about |
|---|---|---|
| 3b | May 16 | May 16 |
| 4a | May 12 | May 12 |
| 4b | May 8 | May 8 |
| 5a | May 3 | May 3 |
| 5b | May 1 | May 1 |
| 6a | April 29 | April 29 |
| 6b | April 22 | April 22 |
| 7a | April 16 | April 16 |
| 7b | April 5 | April 5 |
| 8a | March 29 | March 29 |
| 8b | March 16 | March 16 |
| 9a | March 2 | March 2 |
| 9b | February 1 | February 1 |
Tips
- Waiting a week or two past the average date lowers the risk of a late frost; the "1 year in 10" date in our frost date finder is a cautious choice.
- Tomatoes are in Purdue's "tender" group: damaged by frost, and best planted once nights stay above 50°F.
Working back from your date
Once you know your planting date, the rest of the timeline falls out of it.
| When | What to do |
|---|---|
| 6 to 8 weeks before your planting date | Start seeds indoors if you grow your own (about 6 weeks is enough for most varieties) |
| 1 to 2 weeks before | Harden off: put seedlings outside in a sheltered, shady spot for a short time, then a little longer and sunnier each day |
| Planting day | Pick a calm, overcast day or plant in the late afternoon so the plants are not stressed by midday sun |
| The first week or two | Keep a row cover or old sheet handy for a cold night |
Seedlings that go straight from a windowsill to the garden often get sunscald or snap in the wind, which is why hardening off matters even for store-bought plants that were kept in a greenhouse.
How to plant them
- Plant deep. Tomatoes grow roots along any part of the stem that is buried, so set leggy plants deeper than they sat in the pot, up to the first set of leaves. A deeper root system holds up better in dry spells.
- Give them sun. Choose the sunniest part of the garden; tomatoes need full sun to set a good crop.
- Add support at planting time. A stake or cage is easier to put in now than once the roots have spread.
- Water in well, then water deeply and less often rather than a little every day.
If you live somewhere warm
In zones 9 and 10 the bigger risk is heat, not frost. Tomatoes stop setting fruit well in very hot weather, so gardeners there often plant early in the year and again in late summer for a fall crop. Your ZIP code result above shows your frost dates; in the warmest areas it may show that frost is rare.
Sources: Purdue Extension, "Indiana Vegetable Planting Calendar" (HO-186-W, December 2020); NOAA National Centers for Environmental Information, U.S. Climate Normals 1991-2020 (annual/seasonal freeze probabilities); Nebraska Extension, "Tips for starting your garden indoors"; Iowa State University Extension, hardening off tomato transplants.