I had about 4 - 5 Japanese Blueberry trees when I bought my place (they must have been planted very recently before then). I loved them and was told they were low maintenance, etc. So I added a couple. Since then 1 or 2 have died completely and the rest are on their way. They began to get this black soot stuff all over them and nothing I've tried did any good (more water, less water, various sprays, etc.). Never again.