Question
Several of my plants have had problems with dried up leaves, and all around and within the dried areas are tiny black spots that look like dirt, which can be removed by brushing them off of the leaves.  Newer leaves that have the black spots but have not yet dried up and died have a very mottled texture and appearance, as if these spots are eating away at the leaves.  

When I moved this year, I repotted all of my plants in fresh soil, washed the pots, trimmed off all infected areas, and soaked the entire remaining plant (including roots) in soapy water.  This seemed to have cured the problem for about six or seven months up until now.  

While not all of my plants are affected by this problem, some seem to have it repeatedly.  One is (forgive the only name I know) a Wandering Jew, two are different types of ivy-looking things, and another is a rubber plant.  Suddenly I have started seeing the same dried-up leaf problem with the black dirt-like spots.  What is this and what is the best course of action?

The plants are in different areas of the room, and plants next to each of those mentioned seem unaffected.  They are different ages, different sized pots, all receive different amounts of light, but are watered fairly equally.  They usually get fairly dry in between waterings.  That's about all of the info I can think to provide.
Thanks!

Answer
Colleen,

Your problem is scale. It is a sucking insect. They are bad this time of year. You need to pick up a bottle of Neem oil at a garden center and mix it according to the bottle instructions. Then mix the Neem oil equally with rubbing alcohol and put it in a spray bottle and spray the plants every other day for 2 weeks then twice a week for a month. That should kill the insects and any babies that hatch. This is safe to use indoors and will not harm you or pets. Good luck.

Darlene