| A friend gave me a cactus that has a dry white spot on on side. The cactus is very brown on the bottom right below the white spot. What could be causing this to happen. |
| Unfortunately, based on your description it sounds like the cactus is suffering from some type of rot, possibly starting in the roots. This can be caused by either an infection or by overwatering, or by a combination of the two, and usually kills the plant. |
