Growing an avocado plant from a pit often results in a tall, skinny stem with few leaves. This lanky growth habit can lead to a weak plant. The technique of “topping” or “pinching back” involves removing the main growing tip of the central stem to change the plant’s shape. This simple pruning method is beneficial for gardeners seeking a bushier, more manageable houseplant.
The Purpose of Topping
The natural growth pattern of an avocado seedling prioritizes vertical height over side branches, driven by the plant hormone auxin. This chemical is produced in the terminal bud and travels down the stem. This downward flow suppresses the growth of dormant lateral buds, ensuring the plant dedicates energy to growing upward to seek sunlight.
Removing the main growth tip (topping) breaks this dominance by eliminating the source of auxin. With the hormone concentration lowered, the plant’s energy is redirected, forcing dormant buds along the stem to activate. This initiates new lateral growth, resulting in multiple side shoots that develop into a fuller, stronger, and more branched plant better suited for indoor environments.
Optimal Timing for the First Cut
Determining the right time for the first cut is important, as pruning too early can cause stress. The avocado seedling should be well-established before topping, typically reaching 6 to 12 inches (15 to 30 centimeters) in height. This ensures the plant has a sufficient root system and enough leaves to support new growth after pruning.
The plant must also have several sets of fully developed leaves along its central stem. New branches emerge from the nodes just below the cut, requiring adequate energy reserves. Cutting too soon can deplete the young plant’s resources, while delaying the cut too long results in a tall, difficult-to-manage specimen that is harder to reshape.
Step-by-Step Pruning Technique
The physical act of pruning must be done with care. Start by selecting a clean, sharp cutting tool, such as scissors or small pruning shears. Disinfect the blades with rubbing alcohol to avoid introducing pathogens.
Identify the point where new branching should begin, which must be just above a leaf node or a visible dormant bud. The cut typically removes the top two to three inches of the stem, often reducing the plant’s height by about half. Make a clean, straight cut right above the chosen node, ensuring the cut does not damage the node itself. This precise placement channels energy into the bud immediately below the cut, encouraging a healthy new shoot to emerge.
Post-Pruning Care and Expectations
After the main stem is removed, the plant will enter a period of adjustment. Focus immediately on maintaining consistent soil moisture, avoiding both waterlogging and excessive dryness. Placing the plant in bright, indirect light will help it recover and generate energy for new development.
Within a few weeks, new lateral shoots should begin to emerge from the dormant buds. While multiple buds may swell, one or two new shoots usually become dominant, forming the new branches. If the plant continues to grow too vertically after the initial topping, the tips of these new branches can be pinched back later to encourage more branching and maintain the desired bushy shape.