What is a white fungis/moss like substance on Hibiscus bushes?

I have a white moss type substance on my hibiscus, what is that? It's on quite a few branches. If you know what it is, how do I treat it?

What is a white fungis/moss like substance on Hibiscus bushes?
Powdery mildew is only damaging to your aesthetic. It happens when we have damp foliage and not enough heat and breeze to dry it at night. You can remove gray foliage if you like. If you're in a temperate region in the Northern Hemisphere, you're probably ready to bring in your tropical plants anyway. Time to prune them. If your hibiscus are of the winter hardy varieties, I wouldn't spend much time dealing with this, as the first frost will finish the foliage anyway. If you're in a tropical region and would like to clean up the problem more quickly, you can use commercial fungicides with great effect.


Lastly, if we've misdiagnosed and you do have mealy bugs (not whiteflies) there's a different way to go. Mealy bugs can do some damage. They'll look like fuzzy white clumps on the stems, not the foliage. They're easily controlled. Dip a cotton swap or cotton ball in isopropyl alcohol and dab the clumps off the stems with this. Control the water to control the infestation. Overwatering will foster both of these conditions.
Reply:Definitely sounds like powdery mildew. I have never had problems with it on my hibiscus plants, but commonly find it on my crepe myrtles. As mentioned in the previous answer, remove as much of it as you can by pulling off the leaves. Although I have never tried the coffee and beer trick (at least on plants) - it may actually work. I was able to get rid of it by spraying a "Scotts" brand fungicide on the diseased plant. You may buy this product at any local nursery or home improvement store for around five bucks.
Reply:It is a form of fungus and/or mold and the best thing to do is to scrape it off with a butter knife and spread it on your toast, it really does taste great.
Reply:I don't know what 'fungis' is
Reply:if it is a silvery/powdery mildew, it might even be beneficial to the plant because it is preventing insects.





Powdery mildews seem to be specific to a given plant, the ones that grow on roses will not grow on other species.





If the plant is healthy, it does not represent a danger.





Um... wait... is it spanish moss?
Reply:sounds like it might be white flies--if it is then make a solution of a little dishsoap and water diluted and spray the white stuff with it--every day-----
Reply:Whitefly...
Reply:I think it sounds like powdery mildew as well.





It's not all that uncommon at this time of year. Appears on Lilacs, phlox and zinnias, especially. The leaves will eventually fall off. Just rake and dispose of.





I wouldn't worry too much about it.
Reply:Sounds like powdery mildew. Not good. Cut off all affected parts and destroy. (prevents spreading) Put new, fresh coffee grounds around the plant (cheap coffee) and water in with a couple of beers. I'm serious. My Sterling Silver roses had this and coffee and beer cured them. good luck