Topping Technique

Topping is a pruning technique where growers remove the apical meristem (main growing tip) of the cannabis plant, typically when the plant has developed 3–5 sets of leaves. This removal redirects hormonal signals, causing the plant to branch laterally rather than grow vertically, creating a bushier canopy structure. The technique is commonly practiced in indoor cultivation and photoperiod-dependent strains to maximize horizontal space and encourage multiple flowering sites. Topping differs from other training methods like fimming or low-stress training (LST) in terms of timing, cut precision, and recovery period. Breeders and growers often document how different strain architectures—particularly those with naturally compact or tall phenotypes—respond to topping, informing cultivation recommendations.

Breeders select for topping tolerance and branching vigor when developing cultivars intended for small-space or controlled-environment production. Understanding a strain's natural growth structure and apical dominance helps breeders anticipate how plants will respond to mechanical training, supporting better parent selection for consistency.