Question
I have quite a few cactus plants, and on 2 of my larger plants I have found large white patches on them. This just started this year, so I don't know if I am doing something wrong, or if they have some kind of fungus, please help.
Thanks Barbara

Answer
Hello Barbara,
The white patches (which look like cotton} is what is known as cochineal scale. It was actually produced by little black bugs as a protective coating. If you squeeze it (I don't recommend doing so with your fingers), you will see a red liquid that comes out. This infection is fatal to your cactus if spread. Take some dish soap and mix it with water. Place the water in a spray bottle and spray it all over the infections. Then take your hose and blast the water at the cactus and its infected areas.