Depending on the variety, tomato plants grow from 6 inches to 20 feet tall. It's important to know how tall your tomato plant will grow because tall tomato plants become top heavy and must be staked. Stakes need to be tall enough to support the plants when they are fully grown. Tomato trees and indeterminate varieties grow the tallest. Determinate and dwarf varieties do not grow as tall and require less staking.
Dwarf tomato varieties, such as Tiny Tim, Red Robin and Cherry Gold, grow to just 6 inches tall. These cultivars are ideal for container gardens. They produce 1 inch tomatoes. Grow a single dwarf tomato plant in a 5-inch diameter container. Three dwarf tomato plants grow nicely in a 6-inch hanging planter. Dwarf tomato plants do not require staking.
Determinate tomato varieties usually grow from 3 feet to 5 feet tall. Determinate tomato plants, or bush tomatoes, stop growing earlier than indeterminate varieties and produce their fruit all at once. If staking is required at all, 3- to 4-foot stakes are usually sufficiently tall to support determinate tomato varieties. Celebrity, a bushy determinate variety, does not require staking. Celebrity grows up to 36 inches tall.
Tall and sprawling indeterminate tomato varieties continue to grow and produce fruit until it gets cold. They often grow as tall as 8 feet. When trellised, some indeterminate varieties grow as tall as 20 feet. Better Boy is a manageable indeterminate tomato variety. It grows to about 6 feet tall. Another indeterminate, Sweet 100 cherry tomato, grows as tall as 10 feet. The long vines of indeterminate tomato plants break under the weight of the tomatoes if they are not staked or caged. Most indeterminate varieties require stakes a minimum of 5 feet tall.
A tree tomato grows as tall as 18 feet. This semi-woody tree is a tropical plant and is a different species, Cyphomandra betacea Sendt., than garden tomatoes. Stake tree tomatoes to protect the plants' shallow roots and brittle branches from winds. The red tree tomato variety is preferred for fresh eating.