Jade plants (Crassula ovata) are beautiful and exotic, displaying thick, fleshy jade-green leaves. Whether placed in the house, the greenhouse or the patio, jade plant becomes the center of attention. Relatively easy to care for, its green, waxy leaves sometimes become marred with brown spots. The likely culprit, oedema (or edema), is easy to remedy.
Jade plant requires a sunny or bright location. Because it stores water in its succulent leaves, it does best in dry, well-draining soil, requiring infrequent watering. Jade plant is not a heavy feeder and requires only infrequent applications of houseplant fertilizer.
Jade plants with oedema develop small, corky blisters on the underside of leaves. Sometimes the blisters harden and develop into wart-like bumps. Severely affected plants can sometimes develop bumps on the stems.
Oedema is the swelling of plant tissue. When jade plants take up too much water, the internal water pressure, or turgidity, becomes too much for the tender tissues to support, causing damage to internal plant cells. Over-watering and damp soil, therefore, are the cultural causes of oedema. High humidity often inhibits water evaporation from potting media.
Make sure your jade plant is planted in coarse, gravelly soil, such as cactus soil medium. Water jade plant sparingly, letting the soil dry out between waterings. Keep the plant in a sunny location which helps dry out the potting soil. Keep jade plants away from humid locations, such as kitchens and bathrooms, and place in a location that has good air circulation.
The tender tissues of jade plant are sometimes damaged when water droplets on their leaves heat up in the sun and burn. Avoid wetting jade plant leaves by watering at the base. If placed on a patio, make sure the plant is sheltered from hot afternoon sun.