Tomato roots typically grow to a depth ranging from about 12 inches (30 cm) to up to 3 feet (around 90 cm), depending on several factors such as tomato variety, soil type, and growing conditions.

• Determinate tomato varieties usually have shallower roots, growing about 12 to 18 inches (30 to 45 cm) deep

• Indeterminate tomatoes (such as heirloom varieties) tend to develop deeper and more extensive root systems, potentially reaching depths of up to 3 feet (90 cm) or more if soil conditions allow

• Tomato roots grow both vertically and horizontally. The main taproot grows downward while lateral roots spread out near the surface

• Soil type affects root depth: loose, well-drained soils like loam encourage deeper root penetration, while compacted clay soils may restrict depth but encourage lateral spread

• Planting tomatoes deeply (burying 2/3 of the plant) encourages additional root growth along the buried stem, strengthening the root system

In summary, most tomato roots will grow between 12 inches and 3 feet deep, with indeterminate varieties and favorable soil conditions supporting the deepest root systems. For healthy growth, providing at least 12 to 18 inches of good soil depth is generally sufficient, but deeper soil allows for more robust roots and better drought resistance