I have a Cactus Peruvianus (had it for 40 years) about 7' tall.
The stalk in question is 16" from the dying tip to a new growth taper, then goes on for another 12" until it very strongly attaches to the "trunk." The cactus is slender and out of proportion to its height, making it very difficult to handle.
Thanks for your attention.
It sounds as if you have a spectacular plant. Here is what I found on pruning the Peruvanis:
- Cut unwanted or damaged branches at the end of the growth section where a knob forms in the branch, or where the branch connects to another branch or main column. Use a knife for small cactuses, or a pruning saw for large cactuses. Do not use pruning shears; they can damage the cactus.
Saw through the knob directly, or cut large branches in small sections starting at the tip of the branch until you reach the knob. Be aware of the needles while you handle the cactus.
Dispose of diseased or unwanted cactus branches. Set aside cuttings taken for propagation to allow the cut to callus over.
It seems as though you will be able to have another plant from the branch you have pruned away from the main trunk. I hope it works, and good luck.