Tomato plants naturally possess a vining growth habit. Without proper structural support, stems become overburdened by the weight of fruit and foliage. This sprawl causes branches to break, reduces air circulation, and allows fruit to touch the soil, creating an environment ripe for fungal diseases and pests. Providing stable support keeps the plant vertical, improving sunlight exposure and airflow necessary for a healthy plant and higher yield. This intervention ensures the plant’s energy is directed toward fruit production rather than fighting disease.
Identifying the Need: Determinate Versus Indeterminate Growth
The designation of a “tall” tomato plant almost always refers to an indeterminate variety, which possesses a continuous growth pattern. These plants behave like true vines, lengthening throughout the growing season until the first frost, and can easily reach heights between six and twelve feet. They require robust, sustained intervention because they are perpetually growing and setting new fruit clusters. Determinate varieties, often called “bush” tomatoes, grow to a genetically predetermined height, typically three to five feet. Once they reach this fixed size, they concentrate their energy on a single, concentrated fruit set. While determinate varieties are more compact, they still benefit from caging or staking to support a heavy harvest and prevent wind damage.
Essential Support Methods: Cages and Stakes
Staking
Staking focuses on supporting the plant’s main stem, requiring a tall, sturdy post next to each plant. Materials like wooden stakes, metal rebar, or heavy T-posts should be at least six to eight feet tall for indeterminate varieties. The stake must be driven deep into the ground (about 12 inches) and placed four to six inches away from the stem to prevent root damage. As the tomato grows, the main stem must be tied frequently to the stake, usually every 12 to 15 inches, to maintain verticality.
Caging
Caging provides comprehensive support by encircling the plant, offering 360-degree structure for the foliage and fruit. The flimsy, conical cages often sold at garden centers are inadequate for the weight and height of a mature indeterminate plant. Superior support comes from heavy-duty welded wire or galvanized livestock fencing, shaped into a cylinder at least 24 inches in diameter and five to six feet tall. These robust cages allow the plant to grow more naturally, supporting multiple stems and fruit clusters without the frequent tying required by staking.
Advanced Vertical Support: Trellising and String Systems
Trellising systems are typically used for managing multiple plants in a row, maximizing vertical space and simplifying maintenance. The “Florida Weave,” or basket weave, is a cost-effective technique using sturdy posts placed every few plants along a row. Durable twine, such as synthetic baler twine, is woven back and forth between the posts on either side of the plants, creating a supportive “sandwich” that corrals the stems. A new layer of twine is added every eight to twelve inches of growth, continuing throughout the season.
Permanent Trellising
More permanent trellising involves rigid mesh panels, such as cattle or hog panels, secured vertically between strong posts. These panels offer an immediate, immovable structure that supports the heaviest fruit loads and are ideal for long-term use.
String Systems
For professional or greenhouse settings, string systems like the “lower and lean” method are employed, requiring an overhead support structure like a rafter or pergola. A single string is dropped from this structure to the base of each plant. The main stem is trained to climb the string, often by twisting the plant around it. This single-leader pruning method is highly efficient for maximizing yield and managing very tall plants.
Proper Installation and Ongoing Maintenance
The stability of the support system depends heavily on correct installation timing, which should occur at the moment of transplanting the young tomato seedling. Driving stakes or pushing cages into the soil later risks puncturing or damaging the developing root system. Supports must be anchored deeply—at least a foot into the soil—to bear the eventual weight of a mature, fruit-laden plant that can exceed fifty pounds.
When tying the stem to a stake or string, use a soft, flexible material such as cloth strips, elastic garden tape, or soft twine to prevent stem girdling. The proper technique is a figure-eight knot, where the material crosses between the stake and the stem, creating a cushion that accommodates thickening. For indeterminate plants, ongoing care involves weekly “training,” which means guiding new growth into the support structure or adding new layers of twine to the Florida Weave. This continuous effort manages vertical growth and prevents heavy fruit clusters from pulling branches down.