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Garden Planning, Succession & Crop RotationTransplant Calendar by Crop
Moving a seedling to the garden at the wrong moment sets it back for weeks. Match each crop to frost, soil warmth and its own hardiness.
Key points
- Transplant by frost danger, soil warmth and crop hardiness, not just the date.
- Harden seedlings off for a week or two.
- Transplant on cloudy days and water in well.
- Keep row cover ready for late cold snaps.
What decides when a crop can be transplanted?
Three things: frost danger, soil temperature, and the crop's tolerance of cold. A hardy crop can go out before the last spring frost. A tender crop must wait until frost danger has passed and the soil has warmed.
Your average last frost date is a guide, not a guarantee. Watch the forecast and keep protection on hand.
Where nights stay cool well into spring, wait for steady warmth even if the calendar says the date has arrived.
Which crops go out first?
Cool-season crops such as onions, lettuce, kale and many brassicas can often be transplanted a few weeks before the last frost, with the right protection. Hardiness varies by crop and by variety, so check packets and extension guidance.
Give them a gradual start with hardening off, and cover on cold nights.
Wind can shred young plants as surely as frost can, so site wind barriers or choose a sheltered bed for the first week. A simple row of stakes with fabric stretched between them can work. Check the forecast for the week after planting, not just the day. A warm afternoon followed by a cold night is one of the most common causes of lost transplants, and a few minutes of covering them can save a lot of work.
- Early: onions, lettuce, kale, cabbage family transplants
- Mid: crops that tolerate light cool weather, per your guide
- Late: tomatoes, peppers, eggplant, after frost danger
- Last: melons, squash, cucumbers, after soil is warm
When do warm-season crops go out?
Tomatoes, peppers and eggplant should wait until frost danger is over and nights are reliably mild. Peppers and eggplant in particular dislike cold soil. Squash, cucumbers and melons are even more sensitive and are often set out later or sown directly.
For example, if your last frost usually falls around the middle of April, you might transplant tomatoes a week or two after that and peppers a bit later. This is an illustration of the method, so use your own local guidance.
Cold soil can stall tender plants for weeks, so a thermometer helps you decide when to go ahead.
How do you harden off seedlings?
Hardening off toughens seedlings gradually. Over about a week or two, set the plants outside for longer each day, beginning in shade and shelter, then moving to sun and wind. Reduce water slightly and bring them inside on cold nights.
Skipping this step often causes sunscald, wind damage and a long recovery.
Planting depth varies by crop. Tomatoes tolerate deeper planting, while brassicas and onions generally want to stay near the depth they grew at in the tray. Check your extension guide for each crop before you transplant. A useful test is to look at leaf color and thickness. Seedlings that have stayed indoors have soft, pale leaves, and after proper hardening they look darker and sturdier. If they still look soft, give them a few more days.
How do you transplant to reduce shock?
Choose a cloudy day or the evening, water the plants and the bed well, and set each plant at the right depth for its crop. Some crops such as tomatoes can be buried deeper, but others need to stay at the same depth as in the tray.
Firm the soil gently, water in, and shade new plants for a day or two if the sun is strong.
Water transplants regularly for the first couple of weeks while roots establish, checking soil moisture by hand.
What protection helps?
Row cover, cloches, and wind barriers can protect plants from cold and wind. Black plastic or other covers can warm soil before planting, and it should be removed or managed as the season warms so it does not overheat the bed. Keep protection ready for a late cold snap.
Be prepared to replant if a frost strikes. A few spare seedlings are cheap insurance. Wire cages or stakes are easier to place at planting time than later, when roots are established and can be damaged. Set supports first, then plant beside them.
How do you plan transplant dates for fall?
Count backward from the first fall frost. Brassicas and other cool-season crops are often transplanted in late summer, and heat can be hard on new plants. Shade, mulch and steady watering help.
Follow local water rules, and use your state extension planting guide for dates for your area.
Keep notes on every planting date and what happened, since next year's dates should rest on your own results.
Sources and further reading
Last reviewed: November 2026. Educational information, ranges only. Confirm timing with your county extension office.