I've got various ages of basil (if you know what I mean!) on my windowsill - the youngest is in modules and some of the plants are beginning to develop a fine spattering of black dots that are pitting the leaf surface. A tomato seed has obviously made its way into this group of modules and it too has this spattering - any guesses please?
No guesses. It's a type of bacteria in genus Erwinia. More than one species can cause these problems so I can't be more precise. They grow in warm, humid conditions. Try to ventilate to let the air dry out and allow the leaf surface to dry too.
thanks John, I've moved them somewhere cooler and drier - perhaps I took Basil being a tender plant a bit too much to heart!!