variegated phlox

I have a volunteer phlox in my garden that has lime green leaves and gold variegation along the edges of the leaves. The leaf color is lighter than any of the other phlox in my garden. Although it came up as a seedling last year and I know little about how it is going to perform so far, I am still excited about it. Any advice on special treatment for the plant? I never do anything to my phlox other than keep them mulched with leaves from our huge black oak, but I want this plant to do the best that it can.