Question
Hello,

I have had my cactus for a little over a year. I am not too sure about the type, but in the pot are 3 footlong skinny green cacti with soft needles. Everything has been going well until recently. There  have been little black spots appearing on one of the cacti. There are about half a dozen of these little black spots appearing randomly near the top of the cactus. They arent any bigger than a few milimeters, but I am concerened. The spots appear to be almost eating into the cactus.

Is there anything I can do? What are they? And should I be worried?

Thank you in advance,

Colby

Answer
Dear Colby,

Black spots might be indicative that the roots are in trouble - as these plants grow, they need more room to grow. Take the plants out of the pot and determine the roots' health. They should be slightly off-white. Additionally, you might want to check to make sure there are no root mealy bugs. Last, make sure the plant is in porous soil and that when you do water it that the plant isn't exposed to cold. These should be in warm environments, at least above 50F.

Let me know if you have any further questions.

Kind regards and thanks for your patience,

Jeff