What is the best fertilizer to use on thornless blackberry bushes? I planted several varieties of thornless blackberry bushes five years ago. The first two years I had tons of huge berries. The past two years they have not developed any blossoms. There isn't any sign of virus or disease. I have cut the canes way back every year and the bushes fill in beautifully. I have garden fabric around them with bark on top. The only other plants in the area are raspberries and blueberries.
Fertilizer for Thornless Blackberry Bushes
Certified GKH Gardening Expert
Here are links to refresh you on the care requirements and pruning practices.