Pruning indeterminate cherry tomatoes is a garden practice that greatly improves both the health and yield of these vigorous plants. Unlike their bush-type relatives, indeterminate varieties are climbers that require a structured approach to prevent them from becoming an unmanageable, tangled mass of foliage. By directing the plant’s energy away from excessive leaf and stem growth and toward fruit production, you can ensure a consistent, high-quality harvest throughout the season. Applying specific pruning techniques manages the plant’s size, maximizes air circulation, and reduces the risk of common diseases.
Understanding Indeterminate Growth
The term “indeterminate” describes the plant’s growth pattern, meaning it will continue to grow vertically and produce fruit until it is stopped by cold weather or disease. This vining habit is distinct from “determinate” varieties, which grow to a fixed height and stop producing new foliage and flowers once a terminal flower cluster forms. Indeterminate cherry tomatoes require consistent training and support, such as staking or caging, to manage their continuous upward and outward growth. Without intervention, the plant quickly becomes dense, which shades lower fruit and limits the plant’s ability to efficiently photosynthesize. Pruning is a necessary maintenance task that focuses the plant’s resources, ensuring that the fruit receives sufficient energy for optimal size and flavor.
Identifying and Removing Suckers
The most frequent pruning task for indeterminate tomatoes is the removal of suckers, which are small, new growths that originate in the leaf axil. The axil is the junction where a leaf branch meets the main stem of the plant. If left to grow, these suckers will develop into full secondary stems that compete with the main stem for water, nutrients, and light, creating an overly dense plant structure.
Suckers are easiest to remove when they are small, ideally less than four inches in length, and can usually be pinched off cleanly with your fingers. This method is quick and minimizes the wound size on the plant, which promotes faster healing. For larger suckers, or if the plant’s tissues are tough, use clean pruning shears to make a precise cut close to the stem. Always disinfect shears between plants to avoid the spread of potential pathogens.
While the single-stem approach involves removing all suckers to concentrate growth entirely on the main leader, many home gardeners find a two- or three-leader system more productive for cherry tomatoes. To achieve this, select one or two strong suckers located below the first flower cluster to keep, and remove all others. These retained suckers will then act as secondary main stems, increasing the plant’s overall fruiting capacity while still maintaining a manageable structure.
Managing Plant Height and Density
Managing the overall structure involves removing foliage to improve air circulation and implementing late-season height control. Removing the lower leaves on the main stem helps prevent soil-borne diseases such as early blight and Septoria leaf spot. Leaves that touch the ground, or those within the first 12 to 18 inches of the soil line, are most susceptible to fungal spores splashing up during watering or rain events.
Removing these lower leaves creates a “bare stem racetrack,” which allows air to move freely beneath the canopy and prevents moisture from lingering on the foliage. It is recommended to remove leaves up to the first set of fruit or flowers, ensuring the removal is gradual to avoid shocking the plant. By removing only one or two leaves per week, you maintain enough foliage for photosynthesis while achieving better sanitation and airflow.
Late in the growing season, a technique called “topping” the plant signals the end of vertical growth and encourages the ripening of existing fruit. Topping involves cutting off the main stem’s growing tip, typically 40 to 50 days before the expected first frost date. This action stops the plant from producing new flowers and fruit that will not have time to mature, redirecting the remaining energy reserves into the fruit already set on the vine.