Topping cannabis plants is a high-stress training technique that redirects a plant’s energy from a single main stem into multiple robust branches. This method involves the removal of the plant’s main growth tip, called the apical meristem. This physical removal breaks the plant’s natural tendency toward “apical dominance,” which typically makes cannabis grow in a tall, Christmas-tree shape with one main cola. Removing the apical meristem stops the production of the growth hormone auxin, which suppresses the growth of lower, lateral branches. With the flow of auxin interrupted, growth energy is immediately redistributed to the two side branches directly beneath the cut, forcing them to become the new main stems.
The Foundation Initial Topping Procedure
The initial cut establishes the foundation for a multi-cola canopy and must be executed correctly. Before cutting, ensure your plant has developed at least four to six true nodes, which provides the stored energy needed for efficient recovery. This topping must only be performed during the vegetative growth phase, as stressing a plant during flowering can significantly reduce yield.
Use a sterilized tool (such as a razor blade or clean pruning shears) to perform the cut and prevent introducing pathogens. A clean, quick cut minimizes the wound surface area and reduces the risk of infection. The removal should occur just above the third, fourth, or fifth true node pair, leaving a small “stump” of stem above the remaining node.
Cutting high above the node helps the plant heal and prevents the main stem from splitting as the two new branches thicken. This creates a fork in the main stem, turning the single vertical growth into two new potential main colas. The plant may temporarily pause vertical growth for a few days as it heals and reallocates its energy.
Strategic Timing for Repeat Topping
Successfully topping a cannabis plant multiple times depends on precise timing and a full recovery between each cut. After the initial cut, allow the plant a recovery period, typically lasting between seven and fourteen days, depending on the plant’s health and growing conditions.
Visual cues are the most reliable indicator that a plant is ready for the next topping. The two new main stems must show vigorous growth and develop at least two or three new nodes. The plant should have fully recovered from any initial droop or growth pause, exhibiting healthy, outstretched leaves and a return to a noticeable daily growth rate.
Attempting a second cut too early, before the new growth tips are fully established, can stunt the plant and significantly prolong the vegetative phase. Repeat the process only when the new growth is strong enough to handle the stress and recover quickly, maintaining continuous, healthy development.
Advanced Branch Selection for Secondary Cuts
Multi-topping is a repeated strategy, often associated with methods like manifolding, designed to double the number of main colas with each cut. Once the two new main branches are established, select the next point of removal on each stem. This secondary topping is performed on the new growth by identifying a node and cutting just above it, ideally leaving two or three nodes on each branch.
By topping both new main stems, you convert the two primary growth tips into four, effectively doubling the potential main colas. For a symmetrical canopy, the cut should be made at the same corresponding node on both stems. This ensures all four resulting branches start at the same height and receive equal light exposure, promoting uniform development.
This procedure can be repeated as many times as desired to achieve a high number of main colas (e.g., turning four colas into eight). Consistent selection of the strongest, most symmetrical nodes is necessary to maintain an even, flat canopy structure. This structure maximizes light efficiency across the entire plant.
Post-Topping Care and Stress Management
Immediate care following each topping procedure is important for rapid recovery and stress mitigation. Since the plant allocates significant energy to wound repair and new growth, slightly increase the nutrient solution’s nitrogen content to support this process. Increase nitrogen moderately to avoid nutrient burn on the stressed plant.
Maintaining high environmental stability, particularly consistent temperature and humidity, helps the plant focus on healing. If the plant shows signs of temporary shock, such as slight drooping, temporarily reduce light intensity or raise the light source. The priority is to provide sufficient light to power the new, accelerated lateral growth.
Monitoring the small wound site for any signs of infection is necessary. Any discoloration or soft tissue at the cut point should be watched carefully. The plant will quickly seal the wound and channel its resources to the new, dominant growth tips.