The past couple weeks, several customers have brought in pieces of Ruellia (Mexican Petunia) with worrisome white splotches on the leaves. At first glance, it could appear to be a fungal issue or even a chemical or paint residue, but that’s not it… Here’s what to look for and our recommendation for treatment.
The white funk is actually a type of growth distortion called erineum caused by tiny mites called eriophyid mites (Acalitus ruelliae). So that means fungicides would be a waste of time and money to solve this issue. We recommend treating organically with All-Seasons Oil Spray (a horticultural oil). Repeat the treatment every 5 to 7 days for a total of 3 treatments, wait until Spring, then cut the plants down to ground level. This should kill the mites and the plants should grow back out and look beautiful again. Another approach would be to use organic Spinosad soap or Bee Safe 3-in-1 Spray to treat the mites, then cut to ground level in Spring and wait for clean regrowth.
-DeAnna
Chrissy says
I live in Florida and have the same issue with my Ruellia. Should I use neem oil or spinosad in the evening? Thank you ????
Jesse says
Hi Chrissy – we recommend treating with All-Seasons Oil Spray (a horticultural oil), ideally in the winter months. Repeat the treatment every 5 to 7 days for a total of 3 treatments, then wait until Spring and cut the plants down to ground level and they should grow back nicely.
Chrissy says
Thank you ????
Deanna says
Having the same problem in Jacksonville Florida, my Ruellia is normally healthy and flowering, just bought some new one from nursey and they also had the white on leaves. One plant is usually full of flowers but they are sparse now. We need some kind of solution for these pests. Its so hot here now and nights are warm as well what should we do now