Pruning is the process of removing suckers, the small branches that develop between the main stem and a branch, from a tomato plant. Tomatoes benefit from pruning--pruning keeps plants contained to prevent exposure to insects and soil diseases and allows tomatoes to focus on growing fruit rather than foliage. Pruning is a beneficial method to growing healthier tomato plants and can be easy.
Prune Staked Plants
Indeterminate tomatoes--tomatoes that continue indefinitely throughout the season--require staking and benefit from pruning in keeping the plant contained. When the plant reaches 1 to 2 feet tall, it's strong enough for pruning. Suckers can be pinched off by hand or with pruning shears. The plants must be watered at soil level after pruning to prevent soil from infecting the open wounds.
Prune Unstaked Plants
Determinate tomatoes will only grow to a certain height and usually stay fairly short. Fruits ripen all at one time. While pruning is unnecessary, it may still be beneficial to concentrate the growth on producing fruit. Pruning also allows more sunlight to reach the plant and improves ventilation. Minimal pruning can be beneficial--pruning should be done lightly by removing suckers that appear on branches where there is little room for growth.
Prune Tops of Plants
At the end of the season, tomato plants often outgrow their supports. Pruning the top of the plant can keep it contained in its support. This type of pruning keeps growth concentrated on the fruit already in production. Only the suckers growing over the top of the support need to be removed.
Prune Plant Roots
A technique used to ripen first tomatoes quicker is pruning the roots. Wait until there are three to four clusters of tomatoes on the plant. Then press a spade into the base of the plant and move around the plant in a circular motion to sever some of the roots. The plant reacts by maturing the existing fruit on the vine and then takes a break before resuming production again.