27+ Mint Leaves Turning Black. If you blanch with cold water it keeps the mint nice and green and preserves the chlorophyll. When mint starts growing black spots on its leaves, your plants are likely suffering from leaf blight or advanced stages of mint rust.
I have mint drying in a dark closet but the leaves are turning brown.
What causes the leaves of your mint plant to turn yellow? Dry mint leaves in your. Pull the plant out of the pot, if the roots are winding around the pot it is time to chop the plant into about four pieces cut back the top and plant each section in a new pot. If suffering the black spots on the face, take some mint leaves and mash it and apply to the face and after 15minutes wash the face.