When your pepper plant crops have been especially successful, it can be tempting to try and save them from dying in the winter. It’s particularly tempting if you live in a place where the winters really aren’t that bad.
Unfortunately for pepper-lovers, pepper plants will die in the winter in most regions of North America if they are left outdoors. However, with the right indoor care and variety, you may be able to overwinter your pepper plants successfully.
This may surprise gardeners with experience growing peppers. However, the key to success with peppers–indoors or outdoors–is temperature.
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Peppers are a warm-season crop that thrive in mild springs and warm summers. If that doesn’t describe your climate, don’t be discouraged! Peppers can still be a rewarding crop even in zones that experience a wide range of temperatures.
Optimal Growing Conditions for Peppers
Whether you want to grow sweet bell peppers or hot, spicy chili peppers, the optimal growing conditions will be very similar.
It will surprise many North American gardeners to learn that pepper plants are perennials; after a dormant season, they will return in the spring.
However, in the United States and other temperate zones around the world, peppers are grown as annuals because they cannot adapt to low winter temperatures and fewer daylight hours (source).
Peppers are not frost-tolerant at all, but winter temperatures don’t even need to hover around freezing to be fatal to peppers. Once temperatures are consistently below 50℉, pepper plants will die back before dying altogether (source). Seeds planted directly into the soil won’t germinate at all in temperatures below 55℉ (source).
Peppers are related to tomatoes, but grow more slowly. This can be frustrating for gardeners in northern zones where temperatures below 55℉ are common until May or June. Because those low temperatures can return again by September, pepper growers in these areas have a relatively short growing season.
The bottom line is that if you live in an area where temperatures regularly dip below 50-55℉, you can expect your peppers to behave like annuals rather than perennials. You can help the soil retain some warmth by laying down black plastic mulch or other untreated mulch.
Soil and Fertilizer
Peppers grow well in soil that is very slightly acidic (pH level 6.5-7). Break the soil up before transplanting seedlings to help their roots get established (source).
Soil should retain moisture, but drain well. Breaking up the soil before transplanting should help with this.
Compost is the best fertilizer choice for peppers. If a soil test determines that your soil is low in phosphorus, you can apply a fertilizer with phosphorus; if not, phosphorus won’t be necessary.
Nitrogen should be used with caution when adding it to your peppers’ soil. Over-fertilizing with nitrogen will cause your peppers to become bushy and may delay the onset of fruit.
Peppers are also susceptible to the weed-killers in some “Weed and Feed” fertilizers, so avoid fertilizing your peppers with those.
If you’re transplanting seedlings directly into the ground, instead of growing them in a container or raised bed, avoid planting in soils where other nightshades (eggplants, potatoes, tomatoes, tomatillos, or other peppers) have grown within the last three or four years.
This will protect your new pepper plants from harmful bacteria or soil-borne diseases that affect nightshades (source).
Sunlight and Water Requirements
Peppers require full sun (6-8 hours per day). If you are starting peppers from seed indoors, use a grow light and try to maintain a soil temperature of about 80℉ (source).
Consistent, thorough moisture is ideal for peppers. Avoid letting the soil become soggy, but water deeply enough to encourage healthy root development. If your region receives at least an inch of rainfall per week during the growing season, you may not need to water much more.
Peppers planted in sandy soils will need to be watered more often since sand doesn’t retain moisture as well as loam or clay.
Overwintering peppers is definitely worth the effort if you do some pre-planning and dormant-season care.
Overwintering allows your plants to maintain their mature root systems, which will allow them to bounce back more quickly in the spring. It also gives you a better return on the time and effort you’ve already invested in your pepper crops–a win-win!
If your plan is to try to overwinter your peppers, it will be much easier to plant them in containers or portable raised beds. Mature plants can be removed from the ground and re-transplanted, but growers who take that course of action are likely to damage their peppers’ roots quite badly.
When To Move Your Peppers
Peppers are not at all frost-tolerant and will start to die back before temperatures even come close to freezing. For this reason, it’s important to move them to shelter once temperatures are consistently between 55-65℉.
Another indicator that it’s time to move your peppers is the amount of sunlight they receive per day. If you have warm autumns, or you’re just experiencing unseasonably warm temperatures, your peppers will still start to die back if they don’t receive 6-8 hours of direct sun per day (source).
How to Keep Your Peppers
Start by cutting your peppers back. This will reduce the need for nutrients and sunlight during the winter.
If you have a greenhouse, you can move your peppers there, as long as the temperature inside the greenhouse remains around 50-55℉.
Keeping your peppers in a greenhouse is not the only way to overwinter them. You can also keep them with a grow light in a garage or other sheltered place.
Cut back on watering. Your plants won’t need as much because they won’t be using nearly as much.
Avoid fertilizing until the spring. Some die-back is normal and not a cause for panic.
What to Expect From Your Peppers During the Winter
If you choose to overwinter your peppers, your goal is simply to keep them alive.
At temperatures near 50-55℉, your mature plants will stay alive under a grow light, but they will enter a period of “stasis.” This means you won’t see any active growth, but your plants won’t die, either.
This may seem disappointing to growers hoping to harvest fresh peppers all winter. However, even if you maintained ideal growing temperatures with grow lights and heaters (which could become very expensive), your peppers would still not produce fruit without pollinators. (See Why Are My Pepper Plants Not Producing? for more tips on troubleshooting issues with producing).
Return your peppers to the outdoors once springtime temperatures return to 55℉ or higher on a consistent basis (source).
You can increase your chances of overwintering success by looking for pepper varieties that can tolerate cooler temperatures. Some nurseries and seed catalogs offer pepper varieties that are cold-hardy, widely adapted, or early to mature. These make great options for gardeners in northern regions with shorter growing seasons.
Most cold-hardy peppers are sweet or mild. You may also have better luck with varieties that produce small fruits, which generally tend to be more tolerant of both cold and heat.
Cold-tolerant varieties include the following:
- Obriy, a relatively new sweet pepper cultivar. Obriy is tolerant of both cold and heat and sets fruit in about 80 days.
- Ratund, another sweet pepper. It produces small red fruits in about 90 days.
- Ace, an excellent choice for short growing seasons. Ace sets fruit in only 50-70 days.
- Highlander, a hot Anaheim pepper that matures in 65 days.
- Carmen, a sweet Italian cultivar that produces fruit in 60-80 days.
- Doorknob, a very sweet heirloom pepper. Doorknob matures in about 85 days.
- King of the North, a very productive sweet pepper that matures in 70-75 days.
Pepper plants can be grown successfully as annuals in all regions of the United States, but overwintering can allow you to maintain your peppers as perennials. With some sheltered space, a grow light, and some care, you can enjoy your favorite peppers for years to come!