I've been raising spinach, kale, chard, radishes and several other plants in a container garden on my patio. Recently, whitish spots started developing on the leaves and spreading. They aren't powdery mildew, but rather the leaf itself changing color, almost as if that part of the leaf has died. This happened immediately after I did an eggshell tea watering on the plants for several waterings. Now, it just keeps getting worse and spreading, and I'm not sure what to do. Any advice you have would be greatly appreciated! Nikki, Colorado
Leaves Turning White in Container Garden
Certified GKH Gardening Expert
It sounds as though your plants may have gotten sunburnt. This is the most common cause of plant leaves turning white, however another cause could be lack of nitrogen or phosphorus in the soil, which a properly balanced fertilizer mix will correct.
If you used the eggshell tea on a very hot day and sprayed it on the plants, some of the calcium may have been absorbed by the leaves.
These articles may give you some tips which will help you positively identify the issue: