I planted a Navaho thornless blackberry bush in the spring and it had been growing great. All of a sudden the leaves started turning brown around the edges and dying. I lost the whole top of the plant, then a new shoot grew out of what was left and grew huge. The whole dying thing stopped. Now it is back and was only effecting the old stem but has now started on the lower leaves of the new. I have searched everywhere and can't figure this out. None of the material or pictures I can find are even close. Help!!!

We fertilized after it started thinking it wasn't getting enough nutrients. When I planted it, though, I put MiracleGro shrub soil in the hole before I put in the bush. But it didn't start with the problem until about six to eight weeks after planting. Thanks for the tip on fertilizing, though. I didn't know that.