I am new to the site, and I have a question about at ponytail palm I have. It is 32 years old, nearly 9 feet tall, and has recently become infected at the top with a white fungus. I believe it is powdery mildew, but I'm not completely sure. Any suggestions for what to do? or where to look for more information so I can identify it and control it?
It may not be powdery mildew, if it is the leaves of the plant would be a grey colour and it wouldn't be harming your plant at all. chances are you have mealy bug, if the white is small white spots or clusters that appear cottony then its mealy bug. This pest does love ponytail palms, feel the white if it is smooshy and kinda sticky then its emaly bug, if its grey and more like a crust on the leaves then its mildew. Hope this helps you out.
Thanks! It is indeed mealy bugs. I have read that these can be eliminated by using alcohol on them. Do you have any suggestions beyond that?
A commercial insectidal soap spray will solve your problem, or your local County Extension Office can mail a bulletin to you on a home-made oil and detergent spray to keep things under control.
Chuck, Thanks for your help. I have used an insecticidal soap and it has eliminated the mealy bugs. Mike
Mealies are not easily eliminated in one shot, there could be very small ones you missed, or eggs that didn't hatch yet. A mealy bug can lay up to 300 eggs and incubation can last up to about 14 days. It's best to keep an eye out for a few weeks in case you have to re-arm yourself, or your plant could become re-infested again in no time and being through this myself, who wants that!
I have been growing five of these for some years - they grow extremely slowly for me - and last two winters they have been covered with mealybugs. I have regularly made insecticidal soap solutions, thoroughly saturated the soil of each plant, drenched the leaves several times, and rubbed every square millimeter of leaf. But a few weeks later they reappear. I think that they must be living somewhere in my house. I have them outside right now - going to bring them in, in a few weeks - and will see how they do this winter.
One thing that has worked for me is the use of a slow-release, granular insecticide. The product I am using pretty much kills anything in the soil, as well as, on the foliage. When the plant is watered, it leaches into the soil, is taken up by the plant and essentially makes the plant poisonous to any little critters wanting to feed on the it. It is made by a company called Bonide and is labeled for indoor use (but works just as well outdoors). http://www.nextag.com/bonide-systemic-houseplant/search-html
I agree with Mark, systemic granular insecticide is the way to go. Mealies can get in the soil and attack the roots as well. This will kill them above and below the soil. If you can't find the Bonide brand, the chemical you want to look for is Dysiston, usually 1% here in Pa. Good luck. By the way, you apply it about every 6 weeks.
