Leaves Turning White

Question

Leaves on various plants are turning white – on some daisies, lemon tree. . . .

Answer 1

Not knowing for sure the extent of your problem, I would venture to guess that your plants may be suffering from powdery mildew. The following article should be of some help to you: https://www.gardeningknowhow.com/problems/get-the-cure-for-powdery-mildew.htm