Question
QUESTION: Hi My castle cactus is looking a little ill, some parts are turning brown and dying and it looks like it has exposed green parts, i'm not an expert but my other cacti are doing great....is it diseased?
sarah

ANSWER: Hello Sarah,
It is probably the brown bark-looking substance that grows on a damaged part of a cactus when the inner part of the plant is exposed (such as if it was scratched, cut, or damaged). Do you know what is causing these damages? It may be a cat, if you own any. Or you might have scratched without noticing. If not, check very closley to see if there are bugs or anything that might be damaging your cacti.

If you have further notice, let me know:)

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QUESTION: I dont own any quadrapeds.   Will it heal itself or how do I unexspose the inner part, i didnt see any bugs when I looked very close.

Answer
If there aren't nay bugs, then it was probably accidently damaged. It will heal, so don't worry about it. If you notice brown, bark-looking stuff, then it is a good sign. Don't expect it to recover to a fresh, green look. It would only be covered with the brown substance I mentioned earlier.