We love blackberries but we have never been successful growing them and now I know why...we have always tried to grow blackberries near our raspberries...I have been reading that blackberries just don't grow very well near raspberries. They like the soil moderate acid 5-5.7
(raspberries like near neutral soil 6.5-7)
It is a good idea to grow mulberries, chokecherries and elderberries near your blackberries this will attract birds away from your blackberries.
I can't wait to start growing blackberries!!