| Several things can cause that. A picture would help a lot. First see if they come off or not. You don't want to freak out about dirt.
When I get a mite infestation, that usually causes black spots on the bottom of Phal leaves. You do want to control that if that is what it is, Mites can take down a collection in no time. A good thing to invest in is some Enstar and Tetrasan. These are two pesticides that are the safest and most effective. Tetrasan is also an Ovacide so you won't have outbreaks later if used correctly. As far as safety, these products are 20 times safer and more environmentally friendly then anything you will find in the local store , including rose spray or mild pesticides. It is expensive stuff, but worth it.
Your black spots may also be a fungus infection, or other possible issues. If the spots start to come through the top of the leaves, be careful.
Ants will also harvest mites and scale, so be aware of any ant problems. |