In Tennessee, the first thing that eats into a pepper harvest is the weather, well before any insect shows up. Nashville averages 40.0 days a year at or above 90 F, and pepper flowers fail to set fruit in that heat. They fail the same way on nights under 55 F. Seed timing, counted back from a transplant date after frost, takes care of most of the rest. Insect pests are not covered by the data this site carries.
The short answer
The hot end
The count comes from NOAA NCEI Climate Normals at the Nashville reference station: 40.0 days a year reaching 90 F or more. That is nearly six weeks of days, spread across the warm months. The figure describes summer heat load, meaning water demand, heat stress and trouble for cool-weather plants. It is not an average summer temperature, and it does not say how those days bunch together. Forty scattered days are easier on a pepper plant than forty in a row.
Utah State University Extension, the authority behind this page, puts the problem plainly: pepper fruit set fails when days run above 90 F. Plants don’t die. They keep growing leaves, sometimes lush ones, and drop the blossoms that open during a hot spell. A gardener who sees flowers on the plant in July and no peppers by August is usually looking at exactly this.
The Nashville number is a reference point, not a promise for every yard. East Tennessee and the Cumberland Plateau run cooler and later in spring than Nashville, and this site does not publish a separate 90 F count for them. Treat 40.0 as the Middle Tennessee benchmark and adjust by what your own thermometer says.
The cool end
Heat is only half of it. The same Extension source says fruit set also fails when nights fall below 55 F. A plant that sailed through a warm June can stall again on a cold night in late spring or early fall, wherever it happens to be flowering at the time.
This site does not carry summer night minima. There is no night-low figure here to hand you, and guessing one from latitude, or from how cold the winters get, would be wrong. Winter lows say nothing reliable about a July or September night. So the cool end is yours to watch. A cheap min/max thermometer placed near the plants records the overnight low without you being outside at 5 a.m., and a week of readings during flowering tells you more than any regional average could.
Both ends matter for the whole growing plan. The ripening time is counted from flowering, not from sowing or transplanting, so a late start pushes the first flowers toward the heat of midsummer. Pair this page with Growing Peppers in Tennessee for the full season, and with Why Peppers Fail to Set Fruit in Tennessee for a deeper look at the flowers themselves.
When to start seed here
Start from the transplant date and count backward. Utah State University Extension says transplants need 8 to 10 weeks indoors, and that they go out when the soil reaches 60 F, after frost. Here is the arithmetic in order:
- Find your last spring frost window. At the Nashville station, NOAA NCEI puts it at March 31 to April 12, using the band where the chance of a 32 F freeze falls between 30 and 70 percent. East Tennessee and the Cumberland Plateau run later, so move your dates later if you garden there.
- Check the soil, not the calendar. Push a soil thermometer a few inches down in the bed. Peppers go out when it reads 60 F, and only after the frost window has passed. The later of the two dates is your transplant date.
- Subtract 8 weeks from that date for the latest sensible sowing. Eight weeks is 56 days.
- Subtract 10 weeks for the earliest. Ten weeks is 70 days.
- Sow indoors anywhere between those two dates. Starting at 10 weeks gives older, sturdier transplants; starting at 8 weeks gives younger ones.
- If a cold snap or wet soil delays planting, don’t sow earlier next time. Hold seedlings a bit longer and keep them lit and watered.
Redoing the math for your county
Take a made-up example. Say the soil in your bed reaches 60 F on April 25, after frost danger has passed. Fifty-six days back is February 28, and seventy days back is February 14. Your sowing window runs from mid-February to the end of the month. Now try the Nashville frost window alone: April 12 minus 8 weeks is February 15, and minus 10 weeks is February 1. If the soil is still cold on April 12, the real date slides later, and so does the sowing.
Swap in your own county’s dates and the same steps work anywhere in the state. The only fixed figures are the 8 to 10 weeks and the 60 F soil reading. Everything else is your yard. For help choosing plants that fit the window, see Pepper Varieties That Ripen in a Tennessee Season.
What goes wrong here
Three failures account for most of the disappointment in a Tennessee pepper bed, and each one traces back to heat, a cold night or uneven water.
- Blossom drop. Flowers fall off without setting fruit during a hot spell (days above 90 F) or after a cool night (under 55 F). Remedy: watch your own night lows with a min/max thermometer, and cover young plants on nights that threaten to dip below 55 F. In a stretch of heat, afternoon shade cloth and steady watering help the plant hold its flowers. Don’t pull a bare plant out in July. New blossoms open again once the weather eases, and ripening is counted from flowering, so the fruit still has time to come.
- Sunscald. Fruit exposed to strong sun develops pale, papery, sunken patches that turn tan or gray and invite rot. It shows up most where leaves are thin or have been stripped. Remedy: keep the leaf canopy intact, avoid heavy pruning, and use shade cloth in the strongest afternoon sun. A plant with a good spread of leaves shades its own fruit.
- Blossom-end rot. A dark, leathery, sunken patch forms at the bottom of the fruit, opposite the stem. Swings between dry and soaked soil disrupt how the plant takes up calcium, even when the soil holds plenty. Remedy: water evenly, mulch the bed to hold moisture, and run a soil test before adding any calcium product. Adding it blindly can fix nothing.
What this page does not cover
The title asks what eats pepper, and insects will chew on plants in any state. This site does not carry a Tennessee insect calendar, so no dates or pest counts appear here. Your county Extension office is the place to ask about local pests.
Common questions
What night temperature stops peppers from setting fruit?
Utah State University Extension names nights below 55 F as one end of the failure range, with days above 90 F as the other. This site does not carry summer night minima, so you need to track your own. A min/max thermometer in the bed during flowering gives you real numbers.
When is the last spring frost in Tennessee?
At the Nashville station, NOAA NCEI shows March 31 to April 12 for the band where the chance of a 32 F freeze runs between 30 and 70 percent. East Tennessee and the Cumberland Plateau are cooler and run later than Nashville. Peppers still wait for 60 F soil, which can come after the frost window closes.
Can I store picked peppers in the refrigerator?
The fridge is too cold. Clemson Cooperative Extension gives the best storage conditions as 45 to 50 °F with 80 to 90 percent relative humidity, for two to three weeks (Clemson Home & Garden Information Center). A household refrigerator runs colder than that. Below about 45 °F peppers pit and soften, which is chilling injury. Two to three weeks is a ceiling under ideal conditions, not a guarantee.
Does this page tell me which insects attack peppers?
No. The data behind this page covers heat, cool nights, frost and timing. There is no insect calendar here, and any pest dates would have to come from a source this site doesn’t carry. For identification and timing of insects in your county, ask your local Extension office.