Hi one of my coleus developed a white mold on its stems in the summer. It didn's seem to affect it too much, I cut off the mold parts but when I brought all different coleus in the house in the fall, they all developed the mold on their stems and it killed them all. Now it is on my Hoya and it is a pretty tough old bird about 50 years old, well the original one would be. What is this and how can I get rid of it. Doesn't seem to affect geraniums or Ivy or any of my succulents.
It's hard to tell without a picture or more description. It also might be mealy bugs, try looking them up.
I have a similar problem,my hoya is about 35-40 years old and it has developed a white substance on the stems and leaves. There is also a sticky substance that appears to be associated with it. None of my other plants appear affected. Does anyone have a suggestion on how I can treat it? I pulled it down yesterday to paint my house, so I put it in the shower for a while.
I took a closer look at the substance, I cannot find any bugs on the hoya, the white substance is soft, almost powdery, but it definately has a sticky type substance associated with it. I didn't realize how bad it was until I took it off the wall. (It wraps around a couple of walls on my main floor). It is all over the plant. When you touch it with your finger it pulls away almost web-like, but I don't see any pests.
Mealy bugs tend to look like mold or cotton balls. They may leave a silky web type thing where they have been. They usually also tend to thrive at the "crown" of a plant. They may at times even be attacking the root system. The sticky substance can be sweet for ants and the ants will at times harvest the substance. If ants are also nearby or on the plant its another indication. I have heard people using rubbing alcohol mixed with water, and using a q-tip or cotton ball to wipe the mix on the leaves, this will help remove a few from visible areas, I had a small infestation with my dracaena marginata about 2 months ago. and after using the diluted alcohol and rubbing the cottony critters off of the leaves with the q-tips they seemed to dissappear completely. Water alone usually dont do the trick because these guys have a water repellant surface. There are also other things which can be added to the soil which is absorbed by the plant, then killing the insects sucking the juices out of them. (poisonous to the bug, not the plant) I cant remember the exact name of the chemical but if u google "mealy bugs" im sure their will be an ad for it somewhere.