Tomato suckering is a specific pruning technique employed in tomato cultivation to manage plant growth and optimize fruit production. This practice involves removing new, unproductive side shoots from the plant’s main stem. By eliminating this excess growth, gardeners can influence where the plant directs its energy and resources throughout the growing season.
Anatomy: Locating the Sucker
A tomato sucker is a vegetative shoot that emerges from a specific point known as the axil. The axil is the V-shaped joint formed where a leaf stem meets the main, vertical stem of the tomato plant. Suckers begin as small, soft green nubs and will develop their own leaves and flower clusters if left unchecked. It is essential to correctly differentiate a sucker from the main growing tip or a fruiting branch. The sucker grows at an angle from the axil, unlike the main stem which continues its vertical ascent. Misidentifying and removing the main stem can halt the plant’s vertical growth altogether.
Purpose: Why Remove Suckers?
The primary reason for removing suckers is to redirect the plant’s energy toward the development of fewer, higher-quality fruits. When a sucker grows, it becomes a competing stem, demanding water and nutrients that would otherwise be allocated to the main vine and its existing fruit clusters. Unchecked suckers can turn a single-stemmed plant into a dense, multi-stemmed bush, resulting in many small fruits that ripen slowly. Suckering also prevents disease by improving air circulation within the plant’s canopy. Dense foliage traps moisture, creating a humid microclimate ideal for fungal diseases like blight. Removing the excess shoots thins the plant, allowing air to move freely and ensuring that leaves dry quickly after watering. A less congested plant also allows for better sunlight penetration, which is necessary for uniform ripening.
Technique: Step-by-Step Pruning Methods
The method for removing a sucker depends largely on its size. For very small suckers, usually less than the thickness of a pencil, the preferred technique is “pinching.” This involves simply snapping the shoot off cleanly between the thumb and forefinger at its base. If a sucker has grown larger, it should be removed with a clean, sharp tool like bypass pruners or shears to avoid tearing the main stem. A clean cut is important for plant health, as a larger wound can be a point of entry for pathogens. Pruning should ideally be done in the morning on a dry day, allowing the wound to dry and callous over quickly. Gardeners should check their plants weekly throughout the growing season, as suckers grow quickly.
The decision to sucker hinges on the plant’s growth habit, specifically whether it is a determinate or indeterminate variety. Indeterminate varieties, often called vining tomatoes, grow and produce fruit continuously until frost and benefit greatly from frequent suckering. These plants are pruned to one or two main stems to control their expansive growth and focus energy for maximum fruit size. In contrast, determinate varieties, or bush tomatoes, grow to a predetermined height and set most of their fruit at once on the side shoots. Removing suckers from a determinate plant will significantly reduce the overall yield, so this type of plant requires little to no suckering.