Pinching off, also known as pruning or suckering, involves removing specific vegetative growth from a tomato plant. This targeted removal of new shoots is a common technique used by gardeners to manage plant shape and direct energy toward fruit development. When done correctly, this selective pruning practice can maximize a tomato plant’s yield and overall health. It encourages the plant to focus resources on existing structures and developing fruit.
Why Pinching Improves Tomato Production
Removing side shoots redirects the plant’s energy from producing excessive foliage to developing larger, higher-quality fruit. Tomato plants are programmed to grow vigorously, and pinching manipulates this growth to favor fruit production over vegetative growth. By reducing the number of potential new stems, the plant channels more nutrients into the main stem and established fruit clusters. This concentration of energy leads to fewer but often bigger tomatoes.
Pinching also improves plant health by enhancing the microclimate within the plant canopy. A less dense plant allows for better air circulation, which helps prevent common fungal diseases like blight. Increased airflow helps foliage dry faster after watering or rain, creating an unfavorable environment for pathogens. A more open structure also allows sunlight to penetrate deeper, which is important for ripening fruit lower down on the vine.
How to Identify the Parts to Pinch
The growth targeted for removal is called a “sucker,” a small shoot that emerges from a specific anatomical location on the plant. Suckers grow in the “axil,” the V-shaped junction where a lateral leaf stem meets the main vertical stem. If left alone, these tiny, tender shoots rapidly develop into full-sized, fruit-producing branches that compete with the main stem for resources.
Distinguishing a sucker from a flower cluster or the main stem is crucial to prevent accidental damage. A true sucker always originates from the leaf axil at a roughly 45-degree angle. A flower cluster, however, typically emerges directly from the main stem or at the end of a growth point. Regular inspection is necessary because large suckers can grow into secondary main stems, making them difficult to remove without stressing the plant.
Step-by-Step Pinching Technique
The most effective time to remove a sucker is when it is small and succulent, ideally less than four inches long. When a sucker is this size, it can simply be “pinched” off using your thumb and forefinger. This method creates a small, clean wound that heals quickly and minimizes recovery time.
If the sucker is larger and thicker than a pencil, use a sharp, clean pair of pruning shears or scissors. Making a clean cut close to the main stem is important to avoid tearing the plant tissue, which could create an entry point for disease. Disinfecting your tools, perhaps with an alcohol solution, when moving between plants helps prevent the spread of pathogens.
Strategy for Determinate Versus Indeterminate Plants
The strategy for pinching depends on the growth habit of the tomato variety, which is categorized as either determinate or indeterminate. Indeterminate varieties, often called vining tomatoes, grow and set fruit continuously until frost. These types benefit most from regular sucker removal, which helps manage their height and sprawling nature while directing energy into a manageable number of main stems.
Determinate varieties, or bush tomatoes, grow to a predetermined height and set the majority of their fruit within a short, concentrated period. Removing suckers from a determinate plant is discouraged because these suckers contribute significantly to the final yield. A practice known as “topping,” the removal of the main growing tip, can be used on indeterminate plants late in the season to encourage existing fruit to ripen. Topping a determinate plant will stop its growth entirely and limit the harvest.