I had a perfect wall of BlackBerry plants last week, and now they have leaves turning Brown. This is the second time this has happened, and until now thought I'd fixed it with a hydrogen peroxide formula I read about.they are still covered in berries, and I will harvest, but I bet the leaves will continue this until mostly gone. Drainage problem maybe? If I build up the soil will that fix drainage problems or well they be too deep then? They were so perfect and now look awful.local extension agent was not helpful. How can I prevent it from getting worse? Spray I bought also did nothing.