When to Plant Peppers

The rule: warm soil, not just frost-free

Peppers will die in a frost, but the bigger timing risk is cold soil. Clemson notes that peppers grow very slowly during cool periods and should go out only after the soil has thoroughly warmed. Utah State sets the minimum at 60°F. Use the dates for your zone above as the window, then check the soil with a probe-type thermometer before planting.

Air temperature matters too. Utah State says flowers drop when nights fall below 55°F, so plants set out while nights are still cold won’t set fruit until the nights warm up.

When to start seeds indoors

Count back from your planting-out date:

• Clemson and NC State: 6 to 8 weeks before the last frost.
• Utah State: 8 to 10 weeks, aiming for transplants with 6 to 9 leaves that are 5 to 8 inches tall.

Pepper seed is slower than tomato seed and needs more heat. Sacramento County’s UC Cooperative Extension table shows emergence in about 25 days at 59°F, about 12 days at 68°F and about 8 days at 77 to 86°F, with little or no germination at 50°F. Utah State germinates at 80°F, then grows seedlings at 65 to 75°F under lights 2 to 3 inches above the plants for 14 to 16 hours a day.

Harden seedlings off before planting. Utah State notes that transplants with flowers or fruit establish slowly and yield poorly, so pick those off when you transplant.

Getting an earlier start

In cool, short-season areas such as the northern states and mountain West, black plastic mulch laid before planting warms the soil, and row covers or hot caps protect young plants from cool air. Utah State says that with plastic and covers, plants can go out several weeks before the last frost date. Ventilate covers when the air inside goes above 80°F, because heat during flowering also causes flowers to drop. Direct seeding is possible, since Utah State allows sowing about 2 weeks before the last frost, but transplants mature about 4 weeks sooner and are the better choice in cool climates.

Regional timing

Southeast. Clemson recommends spring transplanting statewide in South Carolina and a fall planting only on the coastal plain. A fall crop is not recommended in the Piedmont.

Texas and the Gulf South. Texas A&M advises planting only when all danger of cold weather has passed, and setting fall plants out 12 to 16 weeks before the first expected frost.

Low desert of Arizona. The University of Arizona’s Maricopa County calendar has a late-winter window and a midsummer window for transplants.

Florida and zones 9 to 11. UF/IFAS plants peppers in spring and again in summer in north Florida, in late winter and late summer in central Florida, and from late summer through winter in south Florida. Spring plantings often keep bearing into summer. Fruit set pauses whenever days run above about 90°F.

Planning backward from fall

For a late crop, start from your first fall frost date. Clemson gives 70 to 85 days from transplant to harvest, and colored fruit needs another 35 to 45 days after flowering to ripen fully, according to Utah State. If your season can’t fit that, pick the peppers green. Clemson also notes that whole hot pepper plants can be pulled and hung just before fall frost.