I have a white crystal-like sugar where my scales should be coming up. Not all my plants have it, but a good portion do. What is it? What do I do?
This could be an infestation of Spider Mites. They can lay up to 100 eggs every couple of weeks and these eggs can appear as very fine white salt crystals.
A strong spray of water can be used to dislodge them.
Treatment with horticulture oils or a miticide will help control them.