I need your help!!! I have lots of green house plants. For the past few months, I have noticed a white sticky powder on the leaves. What can be done to prevent this powder? Could you tell me what it's called?

if it looks kind of cotton like then you have some new friends. They are called mealy bugs and they can be nasty. I get them from time to time and this is how I take care of them. I have bought a spray bottle, a big one that you can find in the household suplies section. I fill about an inch with rubbing alcohol and the rest with water. Then I wrap a plasic bag around the base so nothing drips on to the soil. Then sray away. make sure you get the underside of the leaves thats where they like to breed. I do it every other day for a few days, then it should be good to go!!
Good lick and let us know how it worked out!
BJ