Succulents, prized for their striking forms and ability to thrive in arid conditions, have become incredibly popular houseplants. These plants naturally store water in their leaves and stems, a feature that contributes to their reputation for being low-maintenance. However, this same water-storing ability means they have specific environmental and care requirements that, if overlooked, can quickly lead to distress. When a succulent begins to look unwell, the cause is often one of a few common issues related to water, light, or pests, all of which can be addressed through careful observation and timely intervention.
Symptoms of Overwatering and Dehydration
The most frequent source of trouble for succulents relates to water intake, as their adaptation to drought makes them vulnerable to excess moisture. It is important to distinguish between the visual signals of too much or too little water, as symptoms can appear similar. The difference is typically found in the texture and color of the leaves.
Overwatered succulents often display leaves that are mushy, swollen, and nearly translucent, sometimes taking on a yellow or pale color. This occurs because the plant cells absorb water beyond their capacity, causing them to burst and feel soft when touched. If the problem is not corrected, roots suffocate in the waterlogged soil, encouraging fungal and bacterial rot. This rot usually manifests as black or dark brown discoloration starting at the stem base and is accompanied by leaves that drop off easily.
In contrast, an underwatered succulent draws moisture from its own reserves, causing the leaves to look shriveled, wrinkled, and deflated. The lower, older leaves are the first to show depletion, often becoming dry and brittle before dropping off. The soil around an underwatered plant will be completely dry and often pulls away from the pot edges. While both conditions cause leaf drop, an underwatered plant sheds only lower, dry leaves, whereas an overwatered plant drops plump leaves.
Addressing overwatering requires immediate action to halt rot progression. If the stem shows black or brown discoloration, the healthy portion must be severed with a sterile blade, cutting well above the rot line. The severed top must then be allowed to dry and form a protective callus for several days before being replanted in fresh, dry, well-draining soil. For a dehydrated plant, the solution is a thorough soaking until water runs freely from the drainage hole. Follow this with a return to the “soak and dry” method, allowing the soil to dry completely before the next watering.
Issues Related to Light and Growth Patterns
Succulents require bright light to perform photosynthesis efficiently, and insufficient light visibly alters their growth pattern. Insufficient light leads to etiolation, or “stretching,” as the plant attempts to find a brighter source. This results in an elongated, pale appearance, characterized by long gaps between the leaves (internodes) and a weak stem structure. Leaves may curve downward and lose their compact, rosette shape.
Once a succulent has stretched, the elongated growth cannot be reversed, even under perfect light. To correct etiolation, the stretched portion must be pruned off. The remaining healthy base can then produce new, compact growth under better light conditions. The severed top can be propagated by allowing it to callous and root separately. When relocating a light-deprived plant, acclimate it gradually to prevent sunburn.
Excessive light or intense heat, especially if introduced suddenly, can cause acute sunburn, resulting in permanent damage to the leaf tissue. Sunburn appears as white, pale, or black scorched spots or patches on the leaves that are dry and rough to the touch. This damage is irreversible and remains on the leaf until it is naturally shed. By contrast, a controlled increase in light exposure can cause the plant to develop vibrant stress colors, such as reds, purples, or deep oranges, particularly along the leaf edges or tips.
These stress colors are a natural protective mechanism, where the plant produces pigments like anthocyanins to shield itself from ultraviolet radiation. To avoid sunburn, any change in light intensity should be slow, incrementally increasing the duration of direct sun exposure over one to two weeks. Moving a plant from a shaded indoor spot directly into intense afternoon sun will likely cause scorching, so morning sun is preferred for gradual adjustment.
Identifying and Treating Pests and Infections
Succulents can fall victim to biological threats, most commonly sap-sucking pests. Pests like mealybugs and scale insects feed by piercing the epidermis and extracting nutrient-rich sap, which weakens the plant and leaves it vulnerable to secondary infections. Identifying these pests early is important for successful treatment and preventing their spread.
Mealybugs are soft-bodied insects that look like small, white, cottony masses clustered in plant crevices, such as leaf axils or protected stem areas. They secrete a sticky substance called honeydew, which encourages the growth of black sooty mold. Scale insects appear as small, immovable, dome-shaped bumps—often brown or tan—affixed to the stems and leaves, utilizing a protective, waxy shell.
Treatment for both pests begins with immediate quarantine of the affected plant. A highly effective removal method involves using a cotton swab dipped in 70% isopropyl alcohol to gently dab and dissolve the waxy coating of each visible pest. The alcohol kills pests on contact, but the entire plant must be thoroughly inspected, including the undersides of leaves and along the stem. For severe infestations, a thorough spray of the 70% isopropyl alcohol solution can be applied to the entire plant.
Beyond pests, poor air circulation and high humidity can lead to non-root fungal issues. Powdery mildew appears as a white, flour-like dusting on the leaves. Sooty mold, which is black and superficial, is a direct result of honeydew secreted by sap-suckers, and eliminating the insects resolves the mold. Improving airflow and ensuring the soil surface dries quickly helps prevent these fungal problems.