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32 degrees Fahrenheit (0°C) is too cold for peppers. At this temperature, there’ll be a frost that kills unprotected pepper plants.
Yes, of course, you want to start your pepper plants as early as possible and keep them growing as late as you can, but Mother Nature is a force to be reckoned with, and she can surprise you with a late spring frost or an early fall frost.
So you need to know how temperature affects pepper plants, know how to protect your pepper plants from the cold, and be prepared to leap into action to protect your peppers from frost.
I start my peppers early under cover and move them outdoors when I’m fairly certain there’s no chance of frost. But just in case, I place row cover hoops over the plants, so that if there is even a hint of frost, I can quickly and easily cover the tender plants with fleece to protect them.
What Temperature Is Too Cold For Pepper Plants?
The temperature that’s too cold for peppers is 32°F (0°C). This is freezing, and the lowest temperature pepper plants can tolerate. If unprotected, your peppers will definitely die.
If your peppers are exposed, they can experience an extra wind chill or lower air temperatures that result in death from the cold at 37 degrees Fahrenheit (3°C). Between 33 degrees Fahrenheit and 40 degrees Fahrenheit (1 and 5°C), your peppers will suffer cold injury in the short term, and, most likely, death in the long term.
And, even though it won’t kill your peppers, temperatures below 55 degrees Fahrenheit (12°C) significantly slow growth and ripening.
When you plant peppers, they need a consistent temperature of at least 70°F to 75°F (21°C to 24°C) to germinate. Any lower than this and the pepper seeds take much longer to germinate or will just rot in the soil. While in the early stages of growth and during hardening off, keep them above 55°F (12°C), and, ideally, when you plant them out, make sure the daytime soil temperature is a balmy 75 degrees Fahrenheit
| Temperature | Effect on Pepper Plants |
| Below 32°F (0°C) | Death will occur unless protected by covers |
| 33–40°F (1–4°C) | Suffers damage from the cold weather (not death) |
| 41–50°F (4–10°C) | Significantly slows the growth of the plant and fruit |
| 51–59°F (10–15°C) | The flowers will drop off |
| 60–70°F (15–21°C) | An ideal nighttime temperature |
| 71–80°F (21–27°C) | An ideal daytime temperature |
| 81–89°F (27–32°C) | Slightly high daytime temperature. Increased risk of sunscald |
| 90°F (32°C) or above | Flowers fall off the plant |
Can Pepper Plants Survive Frost Damage?
Whether pepper plants can recover from frost damage depends on how mature the plants are and the extent of the damage.
Seedlings and young plants are at greater risk than mature plants, as their tissues are more tender than those of adult plants.
If the pepper plant was only exposed to a light frost for a couple of hours, it may survive if you take care of it and protect it from further cold weather.
If the whole pepper plant freezes, there’s no chance of recovery. When the disaster first strikes, you probably won’t know right away if the freezing temperatures have finished off your pepper plants, so you’ll need to protect them from the cold and keep a close watch on them over the next couple of days. Then you can try to help your pepper plants recover.
If all the leaves are black, your pepper plant is dead as the leaf tissue died from cold exposure. Similarly, if the lower portion of the stem is black, you won’t be able to save the plant, as the lower stem is dead and cannot pass nutrients and water to the rest of the plant.
However, if only the tips or edges of the leaves blacken, you can probably save the plant. If more than a quarter of a leaf is black, prune it off (but obviously don’t remove every leaf on the plant). For leaves with less damage, leave them alone, as they can still help support the growth and vital systems of the pepper plant while new foliage grows.
You should also remove any fruit that turns black. While not the only cause of black spots on peppers, frost will turn pepper pods black and cause rot to set in because the tissue is dead, so get rid of the afflicted fruit before other diseases set in.
RELATED READING: How to Prune Pepper Plants for Optimal Health and Bigger Harvests
Will Pepper Plants Survive Below 50°F?
While it’s possible for pepper plants to survive below 50°F (10°C), they certainly won’t thrive. In the short term, mature pepper plants will drop their flowers at 51 to 59 degrees Fahrenheit (10 to 15°C) so, that by the time the temperatures reach 50°F (4°C), their potential for fruit production has already significantly reduced.
Between 41 and 50°F (4 to 10°C), the pepper plant can technically survive, but its growth will slow, even with short-term exposure. And, if exposed to these temperatures for a longer period, the plant is both stunted and tough, as is the skin of any fruit still clinging on and trying to ripen. While 50 degrees Fahrenheit won’t kill pepper plants, it won’t help them, either.
Peppers need a fairly long growing season, so if you’re in a cool climate where there are extended periods of daytime temperatures below 60°F (15°C), then keep your pepper plants warm by growing them indoors or using other methods of protection outdoors.
How to Protect Your Pepper Plants From Frost
Thankfully, there are plenty of ways you can protect pepper plants from cold weather. Even though mature pepper plants stand a better chance of surviving freezing temperatures than young pepper plants, they’re still tender and extremely vulnerable.
Choose Cold-Tolerant and Fast-Growing Pepper Varieties
Grow peppers that stand the best chance of surviving in your climate. If you plan on growing peppers known for their tenderness and that require a longer growing season, you won’t get much success. So when choosing a pepper variety, be smart and go for one with a shorter growing season and that can tolerate cooler temperatures.
Whether you choose a sweet pepper or a hot one suitable for cooler temperatures, you’ll still most likely have to harvest peppers before they’re mature at the end of the season, but that’s fine – a chopped green pepper is delicious in stir-fries, casseroles, tomato sauces, and almost anywhere else that you’d cook a fully ripened pepper.
Here are a few of our favorite cold-tolerant pepper varieties. Many of these have proven successful for growing in the Alaskan interior and are the varieties recommended by the University of Alaska Fairbanks.
| Pepper variety | Time to Maturity |
| Bulgarian carrot pepper | 75 Days |
| Ace pepper | 70 Days |
| Intruder pepper | 82 Days |
| Manzano pepper | 100 Days |
| Yankee bell pepper | 80 Days |
| Serrano pepper | 80 Days |
| Anaheim pepper | 80 Days |
Here are a few of our favorite fast-maturing pepper varieties:
| Pepper variety | Time to Maturity |
| Bell sweet chocolate pepper | 57 Days |
| Early jalapeno pepper | 66 Days |
| Fushimi sweet pepper | 60 Days |
| Shishito Japanese sweet pepper | 60 Days |
| Sweet banana pepper | 60 Days |
| Yellow jalapeno pepper | 70 Days |
| Lemon spice pepper | 65 Days |
| Mild hatch green chile pepper | 75 Days |
RELATED READING: How to Grow Bell Peppers?
Start Seeds Indoors, Early
The first thing to do is check out our post on how to protect your plants from frost to find the first and last frost dates for your area. Once you know the typical last frost date, you can plan your pepper planting schedule.
Ideally, plant pepper seeds around 8 weeks before the last frost date. Starting them around this time lets the pepper seeds germinate and the pepper plants reach a reasonable size before summer hits, significantly extending the growing season.
But remember, you’ll have to protect pepper plants from cooler temperatures as pepper seedlings are even more vulnerable to cold weather than mature ones. Although it’s too cold for pepper plants outside, if you start the pepper seeds undercover, in a heated greenhouse, on a sunny windowsill, or in an unheated grow house on a heat mat, they’ll germinate early.
If you use grow lights (these ones are good value, energy-efficient, and work well) you can increase how much “daylight” your pepper plants get and therefore extend their growing time, so they’ll be well ahead in terms of growth when the times comes to put them outside.
And by the time the last frost has passed, nighttime temperatures stay above 50 degrees Fahrenheit, and the soil temperature has risen sufficiently, your pepper seedlings will be big and hardy enough to be planted out in their final position and start to produce fruit.
Apply Cold Treatment
Yes, I did say that cold temperatures slow pepper plant growth. And that’s true. But, if done correctly with young pepper plants, cold treatment slows growth initially, but creates a much stronger, hardier plant.
But don’t go crazy and freeze your pepper plants!
And only try it if you have a moderate or long growing season. The process takes four weeks, so you don’t have time to properly cold treat and still get a decent harvest if you have a short growing season.
Basically, once you transplant pepper seedlings to a larger pot, they establish themselves, and they’ve got at least three sets of true leaves, you can apply cold treatment. For four weeks, keep the temperature a little cooler than the peppers really like. That’s about 50 to 55°F (10 to 13°C).
This gentle cold treatment doesn’t stop the growing pepper plants, but it does slow down leaf growth. Instead, because of the cooler temperatures, the pepper plant puts its energy into growing a stronger root system and thicker, hardier stems and branches.
Therefore, cold treatment creates a more cold-tolerant pepper plant that’s generally tougher and hardier. Once the four weeks are up, increase the temperature to the sweet spot again to stimulate leaf and fruit production.
Harden Off Your Pepper Plants
Hardening off pepper plants is easy and essential. It reduces transplant shock and helps to create tougher pepper plants that can withstand slightly adverse conditions, including cooler temps. Failing to harden off peppers results in weak plants susceptible to disease and insect infestation, and reduced fruit production.
There’s minimal effort involved, but the process takes two to four weeks. Start early by setting up an oscillating fan to blow gently across the pepper seedlings, run your fingers lightly through them, fluctuate the temperature a little, and, when the pepper plants are big enough and the daytime temperatures are consistently above 65°F (18°C), start moving them outside for short periods, gradually increasing their exposure each day.
Read the full step-by-step guide to hardening off pepper plants here.
Plant Your Peppers in the Right Spot
Peppers like to be taken care of. They don’t like to rough it. They want to be warm and sheltered. Sure, if you grow a cold-tolerant variety like a manzano pepper or a yankee bell pepper, it might do okay in a shady or exposed spot in your yard, but it’ll never thrive because the air temperature and sunlight just won’t be enough for the plant to produce peppers in large quantities.
When thinking about planting your pepper seedlings outdoors, choose a sunny spot that gets at least 8 hours of direct sunlight per day. Make sure you’re planting peppers so that they have sunlight but also some shelter against harsh sunlight and strong wind.
You can companion plant peppers to create a little dappled shade, fend off pests and disease, and generally keep your pepper plants healthy.
Whether you’re growing pepper seedlings indoors or out, you’ll need rich, fertile soil high in nutrients.
RELATED ARTICLE: How to Stop Pepper Plants Falling Over
Use Cloches and Row Covers
If cold strikes a young pepper plant, it might just be game over. Even if it doesn’t freeze, it’ll suffer chilling injury. So, for smaller pepper plants, cover them with cloches to protect them from the cold. This 6-pack of cloches is a good size (10 x 7.5″) and fairly good value.
For larger plants and if you’ve got more than a single pepper plant dotted around your yard, you’ll need row covers for better protection. We like these extra-long 50-foot row covers.
Grow Pepper Plants Indoors
If you have the space, growing peppers indoors in the greenhouse means you can grow most peppers, not just cold-tolerant varieties, and you can keep mature peppers producing fruit for longer. Plus, if you’ve got a short growing season or cool outdoor temperatures, you can still grow peppers and won’t need to waste time applying cold treatment.
Pinch Off Early Flowers
Whether you’re growing hot peppers or sweet peppers, pinching off some early flowers can help to increase your overall yield and toughen up your pepper plant, making it more resistant to the cold.
Again, just like cold treatment, this is only something you should do if you have a long enough growing season. If you have a very short season and you plan to grow your pepper plants outside, skip it.
Otherwise, when the first few flowers start to appear, before you’ve planted the pepper plants outdoors, pinch off those flowers. Yes, that is basically removing the early pepper pods, but it encourages the plant to put energy into developing roots and stems first, giving you a stronger, healthier plant that will keep producing peppers even as optimum temperatures fall and cool weather sets in.
FAQs About Peppers and Frost
Can pepper plants survive 40-degree weather?
Yes, pepper plants can survive 40-degree weather, but they won’t thrive. And they’ll drop all their flowers and may suffer chilling injury, stunting their growth and reducing pepper production.
If you regularly get 40-degree weather during the growing season, be prepared to protect peppers with cloches and row covers, start seeds indoors early, and choose a sunny, sheltered spot for your mature plants.
When should I plant peppers outside?
As a general rule, plant peppers outside two to three weeks after the last frost has passed. Soil temperature should be at least 60°F (15°C), nighttime temperatures should be consistently 50°F (10°C) minimum.
Can peppers grow in cold weather?
Peppers can grow in cold weather, but they won’t thrive. They’ll drop all their flowers, existing fruit will likely rot or be stunted, and you won’t get many peppers per plant. But if you germinate seeds indoors early and protect the plants from frost and cold, then you can grow pepper plants even in cold weather.
Can you grow peppers indoors?
Most pepper plants thrive if you grow them indoors in a heated or unheated greenhouse, as long as the soil is rich and well-fertilized and you don’t let the plants get too hot.
Can green peppers survive frost?
Green peppers cannot survive frost unless you protect plants with row covers or cloches to stave off cold night and daytime temperatures. Remember, peppers prefer temperatures of 70°F to 85°F (21°C to 30°C).
Great article on pepper culture. Thanks