My "experiment" went well for a couple years - I started with 7 blackberries pots like yours. In Dallas, they grow very well with just a little extra moisture if the early summer is dry. But, other things grow well under those conditions and I started having to battle other plants that were growing among the blackberries
. Since blackberries fruit during each cane's second year (and then the cane dies off), I had to let stuff grow until I could see if it was a blackberry sprout or something else. So, the blackberries grew along with lots of other stuff -they got a good start before I got to them to remove them. Then I discovered birds (especially mockingbirds) love the fruit, even if it's not fully ripe. Lots of fruit lost to those pesky critters (there were times when I muttered about whether it really was a sin to kill a mockingbird)
. The final straw - those birds spread the seed in and around the blackberry beds, leading to new plants near the original plants. Also learned that these volunteer offspring of these hybrid plants seem to be much weaker and frequently don't fruit at all.
Finally killed what was left this winter and am deciding what to do with the bed, if I can kill off the other hardier things that invaded early on.
All that said, what fruit I got in the first few years was really good, juicy and worth the initial cost of putting in the beds. The later years of frustration soured me on blackberry-growing however.
