I had my soil tested and was told it was not good for blueberries, so I purchased Coast of Maine Soil for Acid-Loving Plants and 30-gallon grow bags and planted one bush per bag. They were purchased from a nursery in May and have produced a few berries, but they both have rusty-looking leaves. One of the plants has roots just above the soil level. Should I try to pull it up and break up the roots? What else can I do to keep them healthy?