Q.What is the purple on my sweet basil
I noticed this morning I have purple spots on my sweet basil leaves. I have sprayed fungus spray on them in the past. They were wilted yesterday and I watered them last night.
The purple coloring usually indicates a mineral deficiency.
I like to feed my herbs with a little Epsom Salt weekly.
I would caution you: carefully wash the Basil leaves now that you have treated them with a chemical before consuming.
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/epsom-salt-gardening.htm
https://www.gardeningknowhow.com/plant-problems/environmental/leaves-turning-reddish-purple.htm