The dates shown first are for an April 20 frost date, as an example. Choose your own date above and the table updates.
Find your last frost date
Your state's Cooperative Extension office publishes local frost dates. Remember that an average date is a midpoint. Frost can still occur after it, so keep covers handy and wait for warm-season crops.
How these dates work
We count back from your frost date using common ranges. Clemson Extension says tomatoes and peppers go in six to eight weeks before planting time, while other guides give peppers 8 to 10 weeks because they're slow to start. These ranges are general, so follow your seed packet if it differs.
Warm-season crops such as tomatoes, peppers, cucumbers and squash shouldn't go outside until after frost has passed and the soil has warmed. Hardy crops such as broccoli and lettuce can go out earlier. Fast crops such as cucumbers and squash resent root disturbance, so don't start them too early.
Hardening off
Move seedlings outdoors in stages over about a week. Start with a short time in shade and bring them in at night. Tender crops such as tomatoes and peppers need this most.