What is that white stuff growing on my___________?

Just fill in the blank. This past weekend was my weekend for "white stuff" (of the plant kind).

Did it just appear overnight - or I have I been paying so little attention? I was working in my yard on Saturday. First I noticed it on my Firebush, then my firecracker plant, and then on my boxwood; then there was that stuff growing on my hibiscus and something else on my crepe myrtle. I have encountered these friends before but I thought I had discouraged them from visiting again. I suppose they were just hibernating all winter and waiting for the opportunity to come out of hiding as the days get warmer.

I always try my best to make an educated guess in identifying plant problems, although there are many with similar characteristics and symptoms

I am quite sure that the stuff' on my fire bush, firecracker and boxwood is all from the same family. It looks like someone took a cotton ball, pulled away some of the cotton, wet it and glued it onto the woody part of the plants. At first, it looks like a fungus of some kind. If you poke at it with a twig, you will see a little white alien looking creature start crawling away. My best educated guess tells me this is a planthopper. Technically, they are suppose to hop away, but mine just crawled. Surprisingly, they are not too harmful to your plants. You can blast them away with a water hose. I usually try to cut away the parts that are heavily infected. I think it makes me feel better, just in case I misdiagnosed.

The creatures that invaded my hibiscus are a different story. My plant has something on the backside of the leaves that looks like thin wispy sections of that white polyester fiber used to stuff pillow cushions. A closer inspection reveals a white spiral pattern which are eggs. When I shake the plant, "white flies" fly away. This is (appropriately name) the giant white fly. They damage plants by sucking the sap and leaving behind a sticky liquid that can promote black sooty mold. Again, I cut away the infected branches. I plan to watch it and if necessary treat it with an all purpose insecticide. A more gentle treatment is to wash it away with a heavy stream of water and/or treat it with an insecticidal soap.

The white stuff growing on my crape myrtle is not from an insect, but from a fungus. It is powdery mildew and is quite common on some varieties of crape myrtle. Patches of white to grayish powdery growth occur on the surfaces of leaves, flowers and new shoots. Infected parts of the plant are usually distorted and stunted. This fungus thrives in high humidity and mild daytime conditions. It seems I aways see this late spring or early summer. My standard treatment is the same as with other fungi and insects. I cut away the infected branches and try to avoid using chemicals unless absolutely necessary.