Pepper plants are vulnerable to many potential problems throughout the growing season. Sunscald is a common problem that you might encounter when you plant peppers in a sunny location. It also often affects tomatoes and cucumbers. Sunscald is especially common when young pepper trees are brought from indoor environments to the outdoors while there is fruit developing on the plant. So what is sunscald? How do you identify it? And what can you do to prevent it? Let’s cover what you need to know.
Table of Contents
- What is sunscald?
- Sunscald symptoms
- How do you repair sunscald on peppers?
- How to prevent sunscald on peppers
What is sunscald?
A simple way to define sunscald is as the effect of prolonged excessive exposure to the sun. The result is damage that you could compare to sunburn on human skin. Immature leaves and fruits are especially susceptible to sunscald when exposed to full sunlight for the first time.
Peppers like warm temperatures. All plants need sunlight for photosynthesis and most pepper varieties grow best in the 65- to 95-degree Fahrenheit range. High temperatures and light are essential, but too much of either can be harmful. Sunscald is especially common when plants produce fruit in late summer.
Sunscald can affect both the appearance and the texture of peppers. Early on, it is easy to mistake sunscald for other problems; for example, sunscald is often confused for blossom end rot. The difference is that sunscald only affects the side of the fruit exposed to sunlight while blossom end rot is found only near the fruit’s blossom end.
Initial indicators of sunscald will be spots on fruit. If the peppers are immature, the affected areas will sometimes be light green. The spots will grow and the texture of the pepper in the location of the spot may soften. Over time, the spot may turn white. Peppers may crack where sunscald occurs and scars will form at the affected site.
Alternatively, pathogens like mold or bacteria can sometimes enter through the crack and cause the fruit to rot. If there is no rot, the damage is usually only cosmetic and does not cause rot or affect whether the fruit is edible or not. Sunscalded fruits will be safe to consume as long as you catch them before they spoil.
The most noticeable sunscald symptoms will be on the fruit but young leaves may show dry edges. In some cases, the leaves will feel dry to the touch, develop white streaks or may even turn completely white.
How do you repair sunscald on peppers?
Sunscalded peppers cannot be repaired, but you may be able to prevent further damage by protecting the plant and its fruit from excessive sunlight. The only way to deal with sunscalded peppers is to remove them from the plant at the first sign that the fruit has been damaged to keep the problem from worsening.
And again, sunscalded fruits will be safe to consume as long as you catch them before they spoil.
How to prevent sunscald on peppers
Harden your pepper plants
Hardening pepper plants off properly helps to prevent sunscald. Plants grown from seed will usually have to be started indoors to protect them from the last frosts of winter. Because they were started in a very different climate from the one outdoors, they need a transition period to get them ready.
What is hardening off? It’s the practice of bringing young pepper plants outdoors for a short time each day as you transition them from indoors to outdoors. You should leave your pepper plants outside for longer and longer each day until you finally stop bringing them inside when they are fully hardened off. Hardening off makes the process of the peppers acclimating to outdoor conditions gradual instead of sudden. In most cases, the process of hardening off pepper plants will take about two weeks.
Protect the plant’s leaves
Take steps to deal with diseases and pests that may cause your pepper plants to lose leaves. Peppers will become very hot if exposed to the sun and may suffer from sunscald, but peppers protected by dense foliage won’t because of the shade. Plants that have had some of their leaves removed because of disease or pests will be the most vulnerable to sunscald.
The best methods for managing these diseases include rotating your crops, maintaining proper sanitation practices, and using fungicide. You should also plant pepper varieties that are resistant to the diseases that cause leaf loss. A couple of the common diseases that often result in defoliation include septoria leaf spot and early blight.
Choose chili pepper varieties less susceptible to sunscald
Prevent sunscald by planting varieties that are resistant to it, such as those that have dense leaf canopies. Pepper varieties where the fruits point upward (such as tabasco peppers) may be more likely to develop sunscald. These varieties spend much more time in sunlight compared to the varieties that hang down and are shielded by the plant’s leaves.
Consider partly-shady areas to plant
If you do plant peppers that grow upward out of the leaf canopy, consider planting them in a location that receives shade for part of the day. If planting in partial shade is not an option, consider planting taller and faster-growing plants near your peppers so that they can help block out some of the sunlight. Okra and sunflowers are two possible options for plants to use as sun-shields. Limiting the exposure should make sunscald less likely.
You can use shade cloths to protect peppers from direct sun. While peppers need to receive some sunlight, you may want to use the shade cloths during the hottest part of the day. Remove the cloths in the mornings and late afternoons but ensure that the plants stay shaded during the middle of the day.
When you don't have natural shade as an option for your plants, shade cloth is an excellent way to prevent sunscald on peppers.
Water your plants thoroughly
Water your pepper plants thoroughly to encourage the growth of leaves that will protect the fruit from the sun. Drought is another factor in sunscald since it affects the density of a pepper plant’s leaf canopy.
Use fertilizers that encourage both leaf growth and fruit production
Nutrition is another factor in how well the plant can shade its peppers from the sun. Start applying the fertilizer early on in the pepper plant’s life. Early fertilization can help to build up foliage to protect the fruit from harsh sunlight. Without the right nutrients, your pepper plants’ foliage is likely to be thin. Ideally, you want a fertilizer with lots of nitrogen along with phosphorus and potassium. The use of balanced fertilizer is recommended even if your pepper plant is in the ground but it is essential for plants in containers.
| Read more: What is the best soil Ph for peppers?
Spray your plants with Kaolin clay
Spraying your pepper plants with Kaolin clay may shield pepper plants and fruit from the sun and thus prevent or limit sunscald. You will need to wash the Kaolin clay from the fruits before consuming them.