Sunscald usually refers to a few different scenarios. all of these scenarios are caused by intense hot or cold weather. In recent years, the area where I live has experienced subzero Frost and extremely hot summers, making Sunburn a bigger concern among local gardeners. While a quick search on the subject in an internet browser will suggest sunshine is only present on trees, the fact of the matter is many other plants and fruits are sensitive. In the northern hemisphere, the condition is called a southwestern lesion because it often occurs on the southwestern side of a tree trunk. Tomato gardeners are also aware of sunburn damaging their tomato fruit-a condition that could make them inedible. But before we go too far, let’s look at all the scenarios that people consider “sunscald” in each of their contexts.
Sun on trees
The sun appears on the bark of trees. Often referred to as a Southwest lesion, the ailment presents on the southwest side of the tree trunk. The resulting damage is a portion of dead or faded bark on the tree trunk. It also appears as a sunken area with thin bark that has cracked. Dead bark due to sunburn is due to dead tissue due to intense temperature fluctuations that stress the tree. There are two types of sun on trees. One appears in winter, and the other in summer. Let’s look at these and the circumstances in which they arise.
Usually, in trees with thin bark, such as the Birch Paper tree, the sunny winter is sometimes referred to as frost cracking. Often this happens when hibernation is broken in trees when temperatures are not seasonally warm. If a quick freeze follows, the tree will not have time to return to rest, and the cells of the southwestern part of the trunk will be affected by the falling temperatures. Sometimes the damage is minimal, and dead tissue is seen only in the slightly cracked shell. Other times, (especially in thin-barked trees) sunburn can cause an open wound that exposes the inside of the tree and makes it vulnerable to insect, animal and ailment pests.
Younger trees are particularly susceptible to sun damage. As they grow and their bark thickens, the chances that the sun will affect the tree decrease. Older trees nearing the end of their life cycle also experience more sunburn than a tree in bloom.
The summer sun affects the trees in the opposite direction. When active cells in the trunk of a tree thrive in summer and extremely high temperatures strike, the bark becomes too hot, burns in the sun and dies. Like winter sunburn, thin bark trees and young trees are most likely to suffer damage from summer sunburn. In this matter, sunburn is a type of sunburn that leads to cracking of pieces of bark that expose the sensitive parts of the tree. The lack of soil moisture is sometimes the culprit of summer sunburn.
Plants that grow in high heat experience leaf burn because the active cells are overworked by extreme heat conditions. Damage from sunburn in the leaves occurs in the upper part of the plant, and the parts most exposed to the elements. Often the upper leaves of vines and shrubs turn white, while the lower growth remains untouched in the shade of dead leaves. Plants with sunburn are more susceptible to pest strike and are more likely to contract ailments.
Most often in solanaceous plants, such as tomatoes, fruits experience a burn form from a rapid rise in temperature in the summer heat. Damaged areas of vegetables and fruits affected by the sun turn white. They become inedible in the process. Berries, grapes, tomatoes, peppers and all other vegetables can get sunburn under certain conditions. Since the fruits come from plants, it is often the matter that the Sun first appears on the leaves and then spreads to the fruits. If the fruits have sunburn, they are more susceptible to damage by insects and other pests. The damage also makes them more likely to suffer ailment.