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Why Are My Pepper Seedlings Turning Purple

After setting up the seeds, germination, and getting established, noticing something “off” with your seedlings is not a fun feeling. When you’ve put in so much effort, it’s disheartening to think you might not be providing the best care for your seedlings. Perhaps they are wilting, drying, or even discoloring. Why are my pepper seedlings turning purple?

Pepper seedlings can turn purple when there is a nutrient deficiency, usually phosphorus, or if there is an excess of iron. Purple striping can also occur on peppers when temperatures are too extreme, affecting the yield of the crop and the quality.

Continue reading to understand why this happens and what can be done to fix and prevent this phenomenon from occurring.

What causes pepper plants to turn purple?

Plants can turn a variety of colors throughout their life for many reasons. Some plants like succulents can change color when sun-stressed as an adaptation to frequently dealing with harsh sunlight for long periods. Plants such as peppers will have fruits that are different colors at each stage of ripeness. However, purple isn’t the most common color and is usually an indicator of poor nutrient availability or too much heat.

Nutrient deficiencies can cause plants to express colors they wouldn’t express under normal circumstances; commonly, this deficiency in phosphorus causes purple coloration. If your soil has too much iron in it, this can also bind up the phosphorus from being usable by your plant. This further stresses the importance of using well-balanced fertilizers for your specific plant type.

Too much heat can cause purple striping in what is usually a green pepper. The heat causes different pigments in your pepper to be expressed, and the purple pigment, called anthocyanin, is more expressed under extreme heat. This also can negatively impact the flavor of the pepper and the yield of the whole plant, so while heat is necessary for peppers, too much can be detrimental.

How do you fix purple leaves?

The first part of fixing an issue is identifying the cause. Too much heat and poor nutrition are the leading factors in purple leaf discoloration. Fortunately, it is evident that something might be going on, so intervention is likely to happen swiftly.

If the issue is heat-related, put your seedlings in a cooler place or in the shade if they are outside in pots. If they are in the ground, you can add mulch to your plant, ensuring you are covering the whole root system. Mulch will help retain the moisture in your soil and keep it cool, which prevents your plant’s roots from drying out.

Poor nutrition can be fixed by amending your soil, which can be done using additives such as bone or fish meal since they are good sources of phosphorus. However, compost can also give your plant the amount of phosphorus needed to thrive and other essential nutrients.

Under-fertilizing has its issues, but so does over-fertilizing. Do not over-compensate for lack of nutrients by fertilizing your plant twice a week; this is more likely to cause root damage thanks to salt build-ups. Always read your product’s label before use, and if you’re concerned about over-fertilizing your plant, you can also reduce the amount of fertilizer called for by half.

Though purple leaves might be jarring, it is a relatively easy fix compared to other more severe issues your plant could be facing.

Tips to prevent seedlings from turning purple

Proper care and nutrition are vital to the overall health of your seedlings, so you will want to set them up for success early on, starting with their potting mix.

Potting mixes for seed starting can be found in gardening and home improvement stores. These mixes are often geared towards moisture retention since germinating seeds and seedlings need consistent moisture to stay alive. One can also make their own seed-starting mix using compost, vermiculite, perlite, and peat moss in a ratio of 4:1:1:2. The perlite allows for drainage; compost provides nutrients; peat moss and vermiculite help with moisture.

On the topic of nutrients, keeping your seedlings well-fed is critical in maintaining a consistent, even color throughout your peppers during all stages of growth. A balanced fertilizer can be used once your seedlings are about 3-4 inches tall. Always follow your product’s label for use and frequency of application.

Maintaining a warm environment helps speed up the germination process and supports the growth of your seedlings. Too much of a good thing can manifest itself as damage or discoloration in your plant, which can happen with heat. Keep your plant out of extreme temperatures by being mindful of where it is planted and your pepper’s needs. Mulching around the base of your plant can also retain moisture in the soil and keep the roots from heating up.

Staying vigilant and keeping in tune with your plants will let you know when something is off and what specific parameters will need to change for your plant’s benefit.

Can pepper seedlings get too much light?

Yes, pepper seedlings can get too much light and scorched or damage their photosystems, leading to distorted growth, a lack of development, or signs of damage such as sunburn or discoloration. Many of these conditions cannot be reverted, so finding the right amount of light for your pepper seedlings is crucial.

Plants need a period of darkness to regulate their own physiological processes, just like humans and other animals. Aim for giving your peppers 12-16 hours of light a day, and the rest of the time should be dark to allow your pepper plants to rest. Following this natural circadian rhythm will help your plant better regulate its physiological processes, leading to better growth and a more vigorous plant in the future.

If using grow lights, be careful not to have the lights positioned too close to the plant, especially if they are not LEDs and give off some heat. Heat-related stress combined with excessive light can severely damage plants, especially seedlings. If you begin to see scorching, leaf curl, or discoloration in the leaves, these are signs of too much light exposure, and you should take care to adjust the light immediately.

Final Thoughts

Parts of your plant turning purple is usually a sign your plant needs some help, often in the form of nutrition or temperature management. These are simple fixes that can profoundly impact your seedlings’ overall quality, health, and yield.

After assessing your plant’s conditions, you should be able to adjust what is causing your plant stress. Over time these signs will get easier to see and diagnose. Though it seems like there might be too much to figure out, learning the ways your plants speak to you ultimately will make you a more effective and intuitive gardener.