Tomato plants are actually upright vines. Supporting the plants keeps the fruit off the ground and prevents the stem from breaking. Tomatoes left to sprawl in the garden also take up more space and are more prone to soil-borne diseases and insects. Staking is one of the least expensive ways to support tomato plants. Purchased stakes, long branches or any other sturdy pole can be used as the stake as long as it is at least 5 feet tall.
Install the stakes prior to planting the tomato seedlings; the stakes may sever roots and damage the plants if installed later. Drive the stake 12 to 18 inches into the ground, leaving approximately 5 feet of stake above ground. Space the stakes at the recommended distance for the tomato variety, generally 2 feet apart for most varieties.
Plant tomato seedlings 4 to 6 inches in front of the stake. Plant the seedlings at the same depth in the garden bed as they are planted in their nursery pots.
Prune the tomato seedling to one main stem, using a clean pair of shears or by pinching off offshoots with your fingers. Remove the new stems that grow in the intersection of the main stem and the branches, otherwise these develop into secondary stems.
Tie the tomato stem to the stake at 6- to 8-inch intervals with garden twine or cloth plant ties. Loop the twine around the stem and the stake, crossing the twine over itself between the stem and stake. Tie loosely so the twine doesn't snap the stem as the tomato grows.