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How to Harden Off Pepper Plants: 6 Things to Know

Nothing is quite as rewarding as growing fruits and vegetables yourself at home, and peppers are one of the most fulfilling. Once your peppers start to sprout, it’s time to start thinking about moving your pepper seedlings outdoors. Did you know there’s a right way to move peppers outside, often referred to as hardening off?

Hardening off prepares indoor plants for external conditions. To properly harden off pepper plants, expose your seedlings to an hour of indirect sunlight, then increase the amount of time they spend outside by an hour every day. If your plant starts to wilt, keep it inside to recuperate and restart the process.

In this post we’ll discuss how to harden off your pepper plants safely. You’ll also learn when to harden them off, why it’s crucial, and what happens when you don’t harden off your pepper seedlings.

Photo  of small pepper plant in a small green pot sitting outdoors in the sun

Step-by-Step Guide to Hardening Off Pepper Plants

When hardening off pepper plants, keep a close eye on how much sunlight and wind exposure your plant gets. If you don’t measure the time it spends outside, it could face severe damage or even death.

Never try to harden off pepper plants when the temperature is lower than 45 degrees Fahrenheit (7 degrees Celsius). When it’s too cold outside, your seedling will be shocked by the climate, and it could die as a result. When hardening off your pepper plants, monitor the temperature carefully and only put your pepper plants outside on warmer days to avoid cold damage.

You should also start watering your pepper plant less when you’re trying to harden them off. Watering the plant less will stunt its growth a bit, allowing it to focus on hardening its leaves instead of growing taller. Excess water in the pot is makes the plant more sensitive to temperature change, and high humidity in the soil can quickly freeze or chill your seedling’s roots. Watering less but still watering enough to keep your pepper plant from wilting can help it harden off better.

It will take at least seven and up to ten days to harden off your pepper plants. Do not rush this process but give your pepper plants the time they need to completely harden off, so that they are not damaged when they are finally transplanted outdoors.  

To safely harden off pepper plants, just follow these simple steps:

  1. On the first day, don’t expose your young pepper plant to direct sunlight, harsh winds, or rain. During the morning or in the evening, place your seedlings in a shady spot for between half an hour to an hour. If it starts to rain or gets windy, bring your plant back inside to prevent damage.
  2. On the second day of the hardening off process, place your pepper plant in the same spot but leave it outside for two hours this time. As before, if the wind starts to blow or it starts to rain, bring your plant inside.
  3. On day three, put your pepper plant outside for three hours. You can also move your pepper plant into partial sunlight. Just make sure that you put your plant out during the morning or evening, when the sun’s rays are less intense.
  4. You may begin to detect a pattern here, but on the fourth day you can increase your plant’s exposure to the outdoors to four hours. At this point, you can also move your plant into a sunnier area.
  5. On day five through seven and up to ten, stick to the pattern of increasing your plant’s sun exposure every day and adding an hour of outdoor time each day. After day seven and up to ten, your pepper plant should be ready to move outside permanently.

If your pepper plant starts to wilt or has brown, crispy leaves, bring it back indoors and keep it inside until it grows fresh healthy leaves. It is essential to nurse back sun-damaged or cold-damaged pepper plants since more sunlight exposure could kill them. After your plant recuperates and starts growing again, begin the hardening off process from the beginning.

What is the Purpose of Hardening Off Pepper Plants?

When pepper plants are germinated indoors, they are not used to cold winds or intense sunlight. If you put your young pepper plants outside on a sunny or cold day after growing them inside, the environment will shock them. The shock can weaken the pepper plant, or worse, cause death. Hardening off is the process of preparing your plants to external conditions gradually, so that they ease into the transition of being outside permanently.

During the hardening off process, your pepper plant’s leaves will get tougher and more rigid as they grow. When plants are slowly introduced to wind, rain, and intense sunlight, they build up thicker, more substantial leaves and stems.

Photo of young pepper plants growing out of brown compost
Photo by Ozii45

When Should You Start to Harden Off Pepper Plants?

Generally, you can start to move your pepper seedlings outside between three to four weeks after they first sprout. You can tell if your pepper plant is ready to move outside if it has shed its seedling leaves, called cotyledons, which are the narrow, smooth leaves that your pepper plant first grows. Once your pepper plant has produced its second set of greener, thicker leaves, it is ready to move outside gradually.

When your pepper seedling has grown its second set of leaves, you can slowly expose it to more sunlight. Under no condition should you put your pepper plant outside without gradually introducing it to the outdoors.

Temperature is another factor to keep in mind when deciding whether or not to start the hardening off process. Make sure that the temperature outdoors is no lower than 45 degrees Fahrenheit (7 degrees Celsius) when you start to move your seedlings outside. If it is too cold, your pepper plant could die from the shock, so it’s always best to monitor the weather and only put your pepper plant outside when you know that the weather will be warm and not windy.

What Happens When You Harden Off Pepper Plants?

When you harden off pepper plants, you are gradually introducing them to the outdoor environment, like the cold and sunlight. Slowly introducing indoor-grown seedlings to the outdoors helps the plants strengthen their stems and leaves so that the wind, cold, and intense sunlight will not damage them. Plants that are hardened off are much more likely to survive and produce more peppers than those that are not.

If you help your pepper plant acclimate to the wind’s harshness, the intensity of the sunlight, and the chill of cold rain, it will become more robust and develop a tolerance to harsher weather.

How Long Does it Take to Harden Off Pepper Plants?

It usually takes between seven and ten days to harden off your pepper plant. The more time you take to harden off pepper plants to the outdoors, the healthier they’ll be. Plants are less likely to suffer from sunscald or get burned by the sun if you slowly expose them to full sunlight.

What Happens if You Don’t Harden Off Pepper Plants?

If you don’t harden off your pepper plants for seedlings that were started indoors, they can quickly die from exposure to the cold, wind, or intense sunlight when you move them outside. If you grow pepper seedlings inside, they’ll become accustomed to the temperature and light exposure they get indoors.

If you place a pepper seedling in direct sunlight after growing it inside, it can quickly suffer from sunscald. Sunscald occurs when a young plant is exposed to more sunlight than it’s accustomed to and gets sunburned. Usually, sunscald will destroy your plant’s leaves, leaving them brown and crispy. Sunscald can kill your pepper seedlings, so monitor how much sunlight your plant gets during the hardening off process.

The wind can also damage your pepper seedlings. If a young seedling is placed outdoors on a windy day, the force of a breeze can snap your plant’s stem, killing it in the process. Because wind can quickly destroy your young plants, only put place your plants outside on non-windy days during the hardening off process.

Closing Thoughts

Hardening off your pepper plants is an essential step for anyone who wants to move young pepper plants outside for the first time. Always harden off your pepper plants gradually and pay attention to the temperature and weather when you start to move them outside to ensure that your plant isn’t shocked by the change. If you harden off your pepper plants correctly, they’ll thrive and produce more peppers.

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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