Tomatillos are a vibrant, tart fruit wrapped in a papery husk, often mistaken for a green tomato but belonging to the species Physalis philadelphica. These plants are relatives of the ground cherry and are a staple in Mexican cuisine, most notably for making salsa verde. Understanding their growth cycle is important for gardeners planning to cultivate them in limited space. The final size of a tomatillo plant is a dynamic outcome of its genetics interacting with its growing environment.
Understanding the Tomatillo’s Growth Habit
Tomatillo plants generally reach a height between three and five feet, though some varieties can stretch up to six feet under optimal conditions. Their lateral spread is often equal to their height, resulting in a bushy, wide profile that requires substantial garden space. A common range of four feet tall and four feet wide better illustrates their overall bulk than height alone.
This wide-ranging size is primarily due to the tomatillo’s indeterminate growth habit. It behaves like a vining plant that continues to grow and set fruit until the first hard frost. Unlike determinate varieties, which stop growing once they reach a predetermined height, the tomatillo’s main stem keeps elongating. This indefinite growth pattern causes the plant to sprawl significantly, often bending branches toward the ground under the weight of the developing fruit.
Without support, the sprawling plant will not focus its energy purely on vertical growth but will branch out horizontally. This tendency to spread wide and become dense is a defining characteristic. Gardeners must plan for this expansive footprint, which contrasts with the more contained growth of a determinate plant.
Key Factors That Influence Plant Height
The actual height a tomatillo reaches is heavily influenced by external variables: sunlight, soil nutrients, and water availability. Tomatillos thrive in full sun exposure (six to eight hours of direct light daily), which encourages the most vigorous vertical growth. Plants placed in partially shaded conditions will often be shorter and less productive as they stretch to find the necessary light.
Soil quality plays a significant role in determining the final size of the plant. Rich, fertile soil that retains moisture provides the energy needed for extensive vegetative growth. An excess of nitrogen fertilizer can dramatically increase plant height and foliage density, sometimes at the expense of fruit development. This abundance of nitrogen promotes the rapid division and elongation of plant cells, leading to a taller, leafier specimen.
Consistent moisture is necessary to support the plant’s large biomass and rapid growth rate. While tomatillos exhibit some semi-drought tolerance, a steady supply of water is required to achieve maximum height potential. Certain varieties, such as ‘Rendidora,’ are known for a slightly more upright habit, while others, like ‘Gigante,’ are naturally more sprawling, demonstrating that genetics establish the baseline for size.
Providing Necessary Support for Vertical Growth
Because of their significant height and sprawling, indeterminate nature, tomatillos require structural support to manage growth and maintain plant health. Without support, fruit-laden branches often rest on the soil, which can lead to poor air circulation and increased risk of fungal diseases. Supporting the plant helps focus its energy on upward growth rather than sprawling along the ground.
One common method for managing size is using large, sturdy tomato cages, ideally three to five feet tall, placed early in the season. The cage provides lateral support for the numerous side branches that develop. Alternatively, staking with a single, tall pole can be used, requiring the gardener to tie the main stems to the stake as the plant gains height.
The Florida weave is another effective technique, which involves sandwiching the plants between horizontal lines of twine strung between sturdy posts. This method is useful for supporting long rows of tomatillos, guiding their branching structure upward and containing their spread. Pruning is a management tool where removing suckers—the small shoots that emerge in the crotch between the main stem and a leaf branch—can help reduce density and manage the overall size of the plant.