Whether you want to start planting peppers early in the growing season or stretch out their production as late into the season as possible, frost becomes a serious concern if you don’t live in a tropical climate. Fortunately, there are ways to mitigate the risk posed by late spring and early fall frosts to your pepper plants.
To protect pepper plants from frost or cold temperatures of 32 degrees Fahrenheit (0 degrees Celsius) or lower, bring them inside if they are planted in containers. If your pepper plants are planted in soil outdoors use insulating mulches and wraps to keep your plants warm and protected.
This article will provide you with six easy ways to protect your pepper plants from frost, which can kill them or severely inhibit their fruit production. Read on if you want to keep your plants safe and your pepper yields high in cooler temperatures.
Bring Pepper Plants Inside Before a Frost
Temperatures of 32 degrees Fahrenheit (0 degrees Celsius) or lower in your garden will cause frost to develop on your pepper plants. Temperatures below 55 degrees Fahrenheit (13 degrees Celsius) will stunt seedling pepper plants and inhibit the growth of mature high yielding plants.
The most effective way to protect your pepper plants from low temperatures is to bring them indoors. You can accomplish this in one of two ways, with the first method beneficial for pepper plants that have not been harvested yet, and the second method helpful to ensuring your pepper plant can be used the following season.
The Potted Plant Approach
By growing your plant in a container, it becomes mobile and can be brought inside before a cold snap. An individual pepper plant requires a pot with a 4-inch or larger diameter to grow successfully and provide a decent pepper yield.
Potted pepper plants allow you to have your plants indoors under more controlled conditions at the seedling stage. It also will enable you to move them outside during the summer months and bring them back in as freezing temperatures approach. Doing so will avoid exposing them to frost.
The Overwintering Approach
Overwintering pepper plants means bringing them indoors over the winter season, after the harvest season is over. It requires you to transplant the pepper plant from its outdoor bed a week or two before the first frost arrives.
This approach is more effective in temperate climates, where fall frosts are rare or easier to anticipate. Also, transplanting an outdoor pepper plant indoors for the winter can create issues with getting the watering levels right—especially for a new gardener. Essentially, it is best to provide the plant with ample light and keep it slightly underwatered during the overwintering cycle. This method is basically meant to keep your pepper plant alive during the colder months, so that you can use it again in the next growing season.
Water Your Pepper Plants Only in the Afternoon
The timing of watering can be used as a tool to help prevent frost on pepper plants.
The reasoning behind this is that wet soil tends to retain more heat than dry soil. When wet, soil can be as much as 5 degrees Fahrenheit (2.7 degrees Celsius) higher than the air temperature. It creates a radiating effect, so if you time the watering right, when the coldest air moves in, the warmer air emanating from the wet soil can be enough to turn the tide against frost.
This method will only work when the temperature drop is within 4 degrees Fahrenheit (2.2 degrees Celsius) below freezing. Since the coldest temperatures typically occur in the hours leading up to and right after dawn, watering in the late afternoon or early evening should provide enough moisture retention in the soil to furnish this sort of protection against frost.
Use Insulating Mulch
Adding a minimum of one inch (2.5 cms) of mulch to the soil will provide a layer of insulation for the soil beneath it. In doing so, more moisture is retained in the ground keeping temperatures elevated above freezing.
For pepper plants, moisture retention helps mitigate freezing temperatures during periods of dryness, peak sunlight, and imminent frost.
Cover Pepper Plants with a Cloche
Gardening cloches are glass or plastic domes designed to fit over plants. When placed over a pepper plant, they trap warm air and provide a buffer for the plant against frost.
Cloches are designed with holes to allow the plant to breathe while covered. If you opt to create your own cloche instead of purchasing one, make sure to add breathing holes.
Use a Blanket or Fleece
Another way to protect your pepper plants from frost is by covering them with garden fleece. Doing so will help your plant stay warm when temperatures drop. It is an effective barrier against late frosts in spring and early frosts in fall.
Lighter and more manageable than plastic, garden fleece places less of a burden on the plant to keep it in place.
Wrap Pepper Plants in Insulating Materials
If a gardening fleece is not available, you can use other insulating materials on your pepper plant. It is best to stick to natural fibers as these will allow your plant to breathe while insulated.
Examples of these alternative insulation materials include newspaper, lightweight cotton fabric, and linen. When insulating your pepper plant in this manner, it is best to cover it before sunset. Doing so will maximize the amount of soil heat that is retained.
Bubble Wrap
Bubble wrap, thanks to its bubbles, is a very effective insulator. When used to cover your pepper plants, the two layers of plastic sandwiching air in each bubble make for superb heat retention.
The downside to using bubble wrap for insulation is that it can overheat your pepper plants if kept on for too long, especially during peak sunshine. It is best to remove bubble wrap in the morning.
Bubble wrap is one of your best options when temperatures are expected to drop way below freezing.
Horticultural Frost Cloth
Horticultural frost cloth is similar to garden fleece. It is usually manufactured out of synthetic fiber, such as polypropylene or polyester. It can be used to stretch over a large bed of pepper plants quite quickly.
Horticultural frost cloth is lighter than plastic, meaning it will not place undue weight on your plants. It is also more flexible and has a more substantial insulating effect than traditional plastic sheeting. If left on during the day, it is less prone to cause overheating.
Burlap
Using burlap tarps over your pepper plants allows you to modulate the insulation you need for adequate frost protection. A single layer of burlap is sufficient when you are facing overnight temperatures near the freezing mark.
When temperatures are expected to drop much lower, using a double or triple layer of burlap will protect your pepper plants against frost more than other materials.
The only drawback to using burlap as frost protection is that it requires you to prepare a supporting structure made of stakes for placing the burlap, as it is too heavy to rest directly on your plants. Also, if wet weather conditions are present, the burlap could freeze. If frozen burlap comes into direct contact with your plant’s foliage, it can cause injury to your plant.
Plastic
The methods mentioned above to protect your pepper plants against frost are more effective than relying on plain plastic sheeting. However, plastic sheeting can come in handy when you are dealing with a large number of pepper plants at once. It can be an economical solution to cover large gardens and provide them with the frost protection they require.
The best way to use plastic sheeting is to construct hoop tunnels that cover an entire bed of plants. To do this, you could use PVC pipe to create hoop frames to support the plastic sheeting over your plants.
Closing Thoughts
Frost can be deadly to your pepper plants. Using any of the methods presented above, you will be able to insulate your plants from frost. In doing so, you will safeguard your pepper plants’ health, extend your growing season, and maximize your pepper production.
Here are Some of my Favorite Gardening Products and Tools
Thank you for reading this article. I hope you found it helpful for growing some new plants in your home or garden. Here are some products I like that I hope you’ll also find helpful. These are affiliate links, and I am compensated for referring traffic. But in all honesty, these are the exact product that I use or recommend to everyone.
Soil: For high-quality soil, I really like Fox Farm Ocean Forest. I do all my growing in containers and this soil has worked great for me. I like how they use nutrient-rich contents like earthworm castings, bat guano, and composted crab and fish.
Fertilizer: Currently I am using a seaweed-based organic fertilizer call Neptunes Harvest. This is a great milder fertilizer option if you want to use something organic. If you want a more powerful fertilizer, I recommend Fox Farm Liquid Nutrient Trio, lots of people have had great growing success with this product.
Pruning Shears: Pruning shears are one of the most useful gardening tools to have because it’s important to prune your plants to keep them healthy. The pruning shears I recommend are the Gonicc 8’’ pruning shears. I like them because they are built sturdy and work both on bigger and smaller plants, so you don’t need to have multiple pruning shears.
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