Suckering is a pruning technique that directs the tomato plant’s energy toward producing larger, higher-quality fruit instead of excessive foliage. This common practice involves removing small side shoots, called suckers, that develop between the main stem and the leaf branches. Properly suckering tomato plants helps manage their size and growth habit, especially for tall, vine-like varieties. This simple maintenance task encourages a more productive plant and improves overall garden health.
Locating and Identifying Suckers
A tomato sucker is a new shoot that originates at the “axil,” which is the V-shaped junction where a leaf stem meets the main, vertical stem of the plant. These side shoots begin as small, soft growths but can rapidly develop into full branches if they are not removed. Visually, you can distinguish a sucker because it grows at an approximately 45-degree angle from the joint, unlike a main branch or a fruit truss.
If you allow a sucker to remain, it will grow into a secondary stem, complete with its own leaves, flowers, and fruit. It is helpful to follow the main stem upward and check every junction where a leaf emerges from the central stalk. The goal is to identify these shoots when they are very small, making them easier to remove and minimizing the open wound left on the plant.
Understanding Why Removal is Necessary
Removing suckers is primarily a practice of energy management, ensuring the plant allocates its resources efficiently toward fruit development. When left to grow, suckers compete with the main vine for water and nutrients, which can result in smaller, later-ripening tomatoes on the primary stem. By eliminating this competition, the plant channels its energy into the existing fruit clusters, leading to a harvest of larger, more uniform tomatoes.
The practice also offers significant benefits for plant health by improving the overall structure and air circulation within the plant canopy. Excessive foliage from unmanaged suckers creates a dense, humid environment where fungal diseases, such as blight, can thrive. Pruning allows for better airflow, helping leaves dry more quickly after rain or irrigation, thus reducing the risk of infection. Controlling the plant’s bushy growth also makes it easier to manage and support the vines with stakes or cages.
Step-by-Step Removal Technique
The technique for removing a sucker depends largely on its size at the time of discovery. The most effective method is to remove suckers when they are still small and tender, ideally less than four inches long.
Removing Small Suckers
When a sucker is small, simply pinch it off using your index finger and thumb, applying pressure at its base to snap it cleanly from the main stem. This method creates a small wound that heals quickly and requires no tools.
Removing Large Suckers
For any sucker larger than a pencil in thickness or over four inches long, use clean, sharp pruning shears. Cutting the sucker off cleanly reduces the risk of tearing the main stem, which could create a larger entry point for pathogens. Sterilize your tools with rubbing alcohol or a bleach solution between plants to prevent the spread of soil-borne diseases. Monitor your plants and remove new shoots at least once a week during the peak growing season.
Suckering Indeterminate Versus Determinate Plants
The necessity of suckering depends entirely on the growth habit of the specific tomato variety you are growing. Always confirm the growth type of your specific tomato plant before beginning any suckering practice.
Indeterminate Varieties
Indeterminate varieties, often called vining tomatoes, grow continuously throughout the season, reaching heights of six to twelve feet until the first frost. These varieties require regular suckering to manage their vigorous, sprawling growth. This ensures the plant’s energy is concentrated on fruit production along one or a few main stems.
Determinate Varieties
Determinate varieties, commonly known as bush tomatoes, grow to a predetermined height, typically around four feet, and then stop. These plants produce the majority of their fruit in a concentrated burst over a short period. The suckers on determinate plants contribute to the overall leaf area and final yield, so removing them is discouraged as it can significantly reduce the total harvest.