A month ago I bought a begonia boliviensis. Very beautiful plant. I had’t even popped it in the ground yet, when I noticed the flowers were dropping. According to what I read that is not uncommon.
Then I noticed powdery mildew. A small bit of powdery mildew can be seen in the upper most leaf. I couldn’t remember how to treat it, so I googled it. Everything I read stated that the plant should be destroyed.
I contacted a friend and he suggested:
“…a mixture of 8oz isopropyl alcohol (70%), 8oz water, 1 Tbsp Dr. Bronners Peppermint castille soap. It works really well on arthropod pests but also has a slight fungicidal effect. Fairly non-toxic to boot.”
I do love peppermint soap, so I gave it a try. Shortly after the application all of the leaves dropped.
This week I started to feel a bit positive about saving the plant. There are a few new leaves.
The leaves appear to be healthy and clear of powdery mildew. Now I wait.