Why Are My Succulent Leaves Turning Brown?

Discovering brown spots on succulent leaves can be concerning, as they often signal an underlying health or environmental issue. Understanding the reasons for this discoloration is the first step toward correcting the problem and restoring the plant’s appearance. This guide will help you diagnose the cause of brown spots and provide solutions for treatment and prevention.

Common Causes of Brown Spots

Sunburn

One of the most frequent causes of brown spots on succulents is sunburn. Like human skin, succulent leaves can be damaged by excessive, direct sunlight. The intense solar radiation damages the plant’s cells, leading to tan, brown, or black patches on the most exposed surfaces. The damaged areas will feel dry and crispy to the touch. A sudden increase in light intensity is a common trigger, such as moving a plant from indoors to a bright outdoor location without a gradual adjustment period. These spots are permanent scars, but the plant can continue to grow healthily once moved.

Watering Issues

Improper watering is another primary source of brown spots. Overwatering is a frequent mistake that leads to root rot. When roots sit in waterlogged soil, they decay and cannot absorb nutrients and water properly, which can manifest as soft, mushy brown spots on the leaves. The leaves may also appear translucent or yellow before turning brown.

Conversely, water droplets left on the leaves can cause browning in a different way. In direct sunlight, these droplets act like tiny magnifying glasses, concentrating the sun’s rays and burning small, circular spots onto the leaf surface. This type of burn is purely cosmetic.

Pest Infestations

Several types of pests can cause brown discolorations on succulent leaves. Scale insects, for instance, appear as small, immobile brown bumps attached to the leaves or stem. These pests feed on the plant’s sap, and the brown bump is a protective waxy coating over the insect’s body, with their feeding causing localized tissue damage.

Spider mites are another common pest. These tiny arachnids are difficult to see, but their damage is more obvious. They pierce the leaf’s surface to feed, leaving behind tiny brown or rust-colored dots, a pattern called stippling. Over time, a heavy infestation can cause entire leaves to take on a dusty, brownish appearance.

Physical Damage and Corking

Sometimes, brown spots are the result of physical injury. A leaf that gets bumped or scratched can develop a brown, callous-like scar as it heals. This is a natural protective response, and the scarred tissue is permanent but does not spread or indicate a health problem.

It is also necessary to distinguish damage from a natural process called corking. Corking appears as a brown, woody texture that develops at the base of a mature succulent’s stem. This is a normal part of the aging process, strengthening the base to support the plant’s weight. Corking is firm and dry, unlike the mushy texture of rot.

How to Treat Succulents with Brown Spots

Once you have identified the cause, you can take steps to address the issue. If sunburn is the culprit, move the plant to a location with less intense light. A spot that receives bright, indirect sunlight or morning sun with afternoon shade is ideal. For overwatering, allow the soil to dry out completely before watering again, and ensure the pot has adequate drainage holes.

Dealing with pests requires a direct approach. For infestations like scale, a cotton swab dipped in isopropyl alcohol can be used to manually wipe the pests off the leaves. This method is effective for smaller infestations.

Existing brown spots from sunburn, physical damage, or past pest infestations are permanent scars. To improve the plant’s appearance, heavily damaged leaves can be carefully removed using a clean, sharp pair of scissors to make a clean cut at the base of the leaf.

Preventing Future Blemishes

Preventing brown spots is centered on providing consistent and appropriate care. One effective strategy is to acclimate succulents to changes in their environment slowly. When moving a plant to a sunnier location, gradually increase its exposure to direct sunlight over one to two weeks to prevent sunburn.

Proper watering techniques are also necessary for long-term health. Always water the soil directly, avoiding the leaves. Many growers use bottom watering, which involves placing the pot in a tray of water and allowing the soil to absorb moisture from the bottom up.

Ensuring good air circulation around your plants helps moisture evaporate more quickly, reducing the risk of fungal problems. Finally, make a habit of regularly inspecting your succulents for signs of pests or discoloration to catch and resolve potential problems early.