White leaves on peppermint plant
I'm a novice container gardener with a 30cm diameter pot of (thriving!) moroccan peppermint on my patio, however, I've noticed recently that some of the leaves are white (or very very pale yellow) and some of the green leaves have small yellowy spots/patches. The patches I notice on upper leaves, the whitish leaves are intermittently spread, and there aren't too many.
Can anyone suggest what this could be? And/or how I can remedy it?