Tomato plants are a staple in many gardens, but success hinges on knowing their growth habit. This classification defines how the plant grows, its final size, and its fruit production schedule. Understanding whether a variety is indeterminate or determinate is paramount for planning garden space, choosing appropriate support structures, and anticipating the harvest timing.
Understanding the Two Primary Growth Habits
The distinction between tomato growth habits is rooted in the plant’s terminal bud, the primary growing point. Indeterminate varieties are often called “vining” types because their main stem continuously produces new vegetative growth. The plant never stops growing until killed by frost, potentially reaching heights of ten feet or more. Fruit production occurs along the entire stem in succession, resulting in a continuous harvest over the season.
In contrast, determinate varieties are known as “bush” types, and their growth is genetically limited. Their terminal buds eventually differentiate into a flower cluster, which stops the stem’s elongation. Determinate plants grow to a fixed, compact height, usually between three and five feet tall. This growth pattern leads to a concentrated fruit set, where most tomatoes ripen within a short, two-to-three-week period.
Identifying Indeterminate Tomato Varieties
Indeterminate tomatoes encompass a vast number of varieties, representing the majority of tomatoes available to home gardeners. Many large, popular slicing tomatoes, commonly known as Beefsteak types, are indeterminate. Examples include ‘Brandywine,’ ‘Big Beef,’ and ‘Better Boy.’ These varieties develop large fruit and require a long growing season to reach maturity.
Most heirloom varieties, treasured for their unique flavors and colors, also exhibit indeterminate growth, such as ‘Cherokee Purple’ or ‘Pineapple.’ The majority of small-fruited types, like cherry and grape tomatoes, are also indeterminate, providing a steady supply of small, sweet fruit like ‘Sun Gold’ and ‘Supersweet 100.’ These varieties are often labeled “Ind.” on seed packets or plant tags, distinguishing them from “Det.” varieties.
Even certain paste tomatoes, typically associated with determinate growth for canning, have popular indeterminate versions, like some strains of ‘San Marzano.’ Semi-determinate varieties also exist; they grow taller than bush types but stop growing earlier than vining types. Indeterminate types are the choice for gardeners who want a prolonged, season-long harvest.
Managing Indeterminate Tomatoes in the Garden
The continuous, vining nature of indeterminate plants necessitates specific garden management techniques, starting with a robust support system. Since the main stem continues to grow, standard small tomato cages are insufficient. Gardeners must use tall, sturdy stakes, strong metal T-posts, or a comprehensive trellis system to secure the heavy vines and their abundant fruit load.
Pruning and Suckers
A common practice for these varieties is pruning, specifically the removal of ‘suckers.’ Suckers are vegetative shoots that develop where a leaf branch meets the main stem. If left to grow, suckers become full, fruit-producing stems, creating a dense plant that can suffer from poor air circulation and disease. Removing some suckers helps focus the plant’s energy into the main stem and fruit development, keeping the plant manageable.
Indeterminate tomatoes offer a steady harvest from mid-summer until the first hard frost. Regular harvesting of ripe fruit is encouraged, as this signals the plant to continue flowering and setting new fruit. Without specialized support and pruning, the heavy vines can sprawl across the ground, making the fruit susceptible to rot and pests.