Tomatoes are warm season fruits that are generally classified as vegetables. The plants are grown as annuals but are actually perennial plants. Tomatoes grow 3 to 10 feet in height and usually have to be staked due to their weak woody stems. They are easy to grow and will thrive under most conditions. There are hundreds of varieties of tomato plants. Most tomatoes have a distinctive red color. For best results, tomato plants should be pruned to reduce the weight on the plant and to provide the best yield all summer long.
Examine your tomato plants every 3 to 4 days for new growth. Look for new growth between existing leaves and the main stem--called suckers. Indeterminate tomato plants continue to grow throughout the season with an unlimited number of stems and suckers, as long as they receive proper care. Determinate tomatoes grow to a predetermined size and require little pruning.
Pinch off these suckers to prevent them from growing into large stems and producing more fruit. This will ensure that your fruit will grow larger. Simple pruning involves removing the entire sucker from the plant at the stem. Simply grasp the sucker where it connects to the stem. Bend it back and forth until it breaks off. Do not use a knife or scissors to cut the sucker off; it can cause disease in the plant. If the suckers have become large and tough, though, remove them with a sharp blade.
Pinch back using "Missouri pruning" if suckers have gotten out of hand. In this method, you pinch off only the growing tip of the suckers and leave the bottom leaves. It causes less of a shock to leave a portion of the sucker than to remove the whole thing. This method increases photosynthesis of the tomato plant because more leaves are available to the sun.
Remove all of the suckers below the first flower cluster when pruning determinate tomato plants. The suckers will not add to the amount of fruit that the plant produces. Flower stems that grow beneath the first cluster will only weaken the tomato plant, so they should be removed.