Familiar to those who have had a sunburn, aloe vera (Aloe barbadensis) plants produce a healing juice packed with vitamin C. Aloe vera is a succulent that is native to North and Central America as well as the Mediterranean regions of Europe. Ironic in its nature, this desert succulent is sun sensitive and will sometimes form brown spots on its leaves.
Brown spots are a sign of internal sunburn damage to the plant. In aloe vera plants, sunburn dries out the skin, making it woody. Brown spot areas are stiffer than the rest of the leaves because the internal tissue is dry. Leaves that are seriously covered in brown spots may become useless.
Brown or orange spots on the leaves are the outward sign of a sunburn on the plant. The brown spots are irregular in size and will typically be the worst on the top leaves. If left unattended, the leaves then crack and form white, woody calluses.
Brown spots can appear anytime of year, but are most likely to occur during the hottest summer months. If the spots are caught early enough, usually when the leave's spots are still orange, then the plant can heal itself overtime when moved to a shadier location. An aloe vera plant takes roughly one month to heal completely from brown spots.
Many home gardeners think that since the aloe vera is a succulent, it must love the sun. While aloe vera plants are drought resistant and do not require much care or upkeep, they are not as tough skinned as other succulents. This is primarily caused by the massive amount of water stored in its comparably thin leaves.
Preventing brown spots is as simple as moving the plant out of the sun. Aloe vera plants do best when only getting the gentle morning sun and being sheltered by afternoon. If the plant is in a position where it receives some afternoon sun, consider constructing a shade fence over the plant that blocks the afternoon sun. Do not give an aloe vera plant extra water as it will cause root rot.