help me understand cane berry lateral growth
Here's my growing situation: I am growing both boysenberries and Triple Crown blackberries in 18 gal containers. Each container sits within a rectangular cage which is about 7 ft tall and a little wider than the container itself.
I only allow four fruiting canes on a plant each season and these are tied to the vertical corners of the cages. New canes that will fruit the following season are directed up the center of the cage until they can take the place of the older canes. Then I choose the four best, cut out the rest, etc.
This is done in a narrow side yard and is the only place I have for growing these plants (long story, evil neighbors, etc.).
My question is about the fruiting laterals. I've read that after tipping the new canes the laterals will develop and that these can then be cut back to perhaps 12-18" in the dormant season. I generally do this for any laterals that have formed, but many canes do not have laterals at that point (maybe because I don't tip the new canes until it's time to remove the old ones?), so when they start growing in the Spring I'm never sure what to do. My initial observation is that flowers seem to form on the terminals of the laterals, so I fear cutting them back will sacrifice fruit.
The other side of that coin is that there is a real tangle now since many of the laterals are quite long :-( This has pluses and minuses as well, but I think more minuses.
So...if I cut back (or pinch out) the tips of newly growing laterals in the Spring, how will the remaining lateral grow? Will it send out side shoots with flower buds or?????