Primocane origin in black raspberry

Is there any easily-accessible science on where primocanes originate on black raspberry and other brambles?

Yes, the “crown” but what constitutes the crown? A couple of mine seem to have new primocanes originating at or slightly above ground-level–basically at what appears to be the very base of the floricane (the growth is way too vigorous and soft to be a low-growing fruiting floricane shoot). Is there some calculation where below a certain point the bud makes a primocane vs a floricane? Or did I just plant them too shallowly?

To me it sounds like it’s planted shallow. I would add mulch.

Black rasps primocanes come from the crown.
Red Rasps primocanes come from crown and roots
Blackberries primocanes come from crown and roots

Root primocanes are suckers…and should be dug out and put alone or removed as they compete with the main cane/crown.

What is the crown- If you dig it up you will see its basically a big mother root mass. The roots feed the crown which feeds the canes.

Primocanes from the crown will be tender and fragile until they harden off and develop.

The crown should be protected by at least an 1/2 to 1 inch or so of material.

In nature it protects itself by leaf fall upon death of floricanes…

That helps. I actually have a bunch of wood chip mulch I’m planning to put over the raspberry bed.

I had straw down before, but I raked up the straw and I noticed the phenomenon I mentioned above. I imagine they’ll be fine once I put a couple inches of wood chips back down.


Yeah it should be fine. I have experienced a sudden death syndrome with black raspberries. The canes just giving it up. It happened with Niwot, Jewel, and Allen. Luckily I made some crosses and my hybrids are not experiencing this sudden death. At least not so far. A few years old now. Berries are actually better anyways.