While pruning tomato plants is not mandatory, plants that are pruned and properly supported will be able to put more energy into fruit production. Each variety of tomato reacts differently to pruning, so you may want to experiment with your favorite types to develop a system that works the best for you. Prune the plants in the early morning or on a dry day to allow the cutting wounds the opportunity to heal cleanly.
Remove the lower two to three branches from the tomato plant at the time of planting by gently pulling them off. This allows you to plant the tomato deeply into the ground to stimulate additional root growth.
Prune tomato plants once they reach a height of 1 to 2 feet by first removing the plant suckers. The suckers are small leaf growths that appear at the joint of two main branches. Pinch suckers off with your fingers to remove.
Remove all branches below the first flower cluster with a hand pruner once plant blossoms appear. Removing lower branches without fruit will increase air circulation around the plants. This also redirects the plant's energy resources to fruit production instead of branch production.
Monitor the plants during the growing season. Remove all yellowing or diseased branches to prevent spreading.
Water tomato plants at the ground level after pruning to prevent dirt and water splashing into the fresh cut plant wounds.