My mint plant in my greenhouse has white powdery stuff on the leaves. Maybe some sort of mold or fungus? Does anyone know what this is? And if so, does it spread to other plants? I put the mint outside the greenhouse just to be safe for now. Any suggestions would be welcome. Thanks in advance.
by No_Roof_8787
5 Comments
Looks like powdery mildew.
Get it out of the greenhouse.
It’s too humid and probably stressed with high temperatures.
It’s mint. It will recover and go crazy as soon as it gets out of a pot.
I agree with it being powdery mildew. Caused by high humidity and wet leaves. Cucumber and related plants seem most susceptible but I’ve also seen it spread to dill and fennel. Supposedly it can spread to tomatoes as well. Moving it out of the greenhouse is the right call. If you see it on any other plants remove affected leaves immediately.
The mint is probably done but can come back after winter and a little sulphur dust in the soil early spring will kill the spores. My understanding is not to use sulphur dust this late in the growing season though. Probably too late and makes the plant inedible including in fruiting plants if flowering/fruiting has already occurred.
powdery mildew
Flavors and green