How to prune purple choy sum

Main shoot harvest at 40–50 days, when flower buds are tight; side shoots in the following 2–3 weeks. Use a sharp knife to cut the main flowering shoot 4–6 inches above a leaf node. Collect side shoots of similar length as they develop. Keep cutting to maintain production; once shoots become thin or flowers open fully, flavor declines rapidly.

Every few days during the harvest window. Purple Choy Sum is harvested at the tender flowering-shoot stage — cut the ornamental purple-tinged main stem before flowers fully open, which triggers productive side shoots. No pruning in the ornamental sense applies. Manage it through timed harvest cuts. Once side shoots are spent or the plant fully bolts, the crop is done.

Use a sharp knife to cut the main flowering shoot 4–6 inches above a leaf node. Collect side shoots of similar length as they develop. Keep cutting to maintain production; once shoots become thin or flowers open fully, flavor declines rapidly.