Hello, it's your Crassula here. I know those brown, crispy, sometimes sunken spots on my leaves are worrying you. Often, this is my way of telling you I've had a bit too much direct sunlight. While I love bright light and need it to maintain my compact shape and vibrant colors, my leaves can get sunburned just like your skin. This is especially common if I'm moved from a lower-light spot directly into intense, unfiltered afternoon sun without time to acclimate. The damaged leaf tissue dies, resulting in those permanent brown or tan scars, usually on the upper leaves facing the light source.
Those soft, mushy, dark brown or black spots, particularly on lower leaves or in the center of my rosette, are a serious cry for help. This is typically a sign of overwatering. When my roots sit in soggy soil for too long, they begin to rot and can no longer absorb water or nutrients effectively. The problem then spreads upwards into my stems and leaves, causing them to break down and develop these rotten spots. Often, this is accompanied by leaves that feel soft and translucent. This condition can quickly become fatal if not addressed.
Sometimes, those unsightly spots are due to an unwelcome microscopic invader. Fungal infections, often encouraged by high humidity and poor air circulation around my foliage, can manifest as irregular brown spots that sometimes have yellow halos or a concentric ring pattern. Bacterial infections might present as water-soaked lesions that later turn brown or black. These pathogens often enter through wounds or are present in contaminated soil. They thrive in the same damp conditions that cause root rot, making overwatering a double threat to my health.
Please don't forget that I can be bruised! A bump, a curious pet, or even rough handling during repotting can cause trauma to my leaves. This damage may not show up immediately but can develop into a brown callus over the following days as the wounded tissue heals and seals itself off. Furthermore, it is completely natural for my oldest, lowermost leaves to gradually yellow and then turn brown as they age and I redirect my energy to new growth. This is a slow, uniform process, not sudden spotting, and the leaf will often dry out completely before dropping off cleanly.
Tiny, sap-sucking pests like mealybugs, scale, or spider mites can also be the culprits. As they feed on my juicy leaves, they puncture the surface and drain my vital fluids. This feeding damage creates small, localized spots of dead tissue that appear brown or yellow. You might need to look very closely, especially in the nooks between my leaves and stems, for the pests themselves or other signs like sticky honeydew or fine webbing.
