Trellising Natchez Blackberry
I potted a Natchez blackberry plant (a semi-erect variety, apparently) this season in Al's 5-1-1 mix not really expecting much - it was a bit sad-looking when I bought it (definitely an impulse buy - it was heavily discounted), and I was under the impression blackberries are hard to deal with, but it has really taken off, sprawling vigorously in three different directions.
It's in a 3 gallon container right now, and I have no idea how to trellis it in such a way that I'll be able to move it easily (we're doing the apartment thing) next year. Do I need to transplant it again into a larger container? Suggestions on the best trellis type?
I am relatively hopeless with this sort of thing - I have never trellised anything before, and my pruning skills are less than desirable.