No question about it, tomato plants (Solanum lycopersicum) grow bushier and produce more tomatoes when you prune them properly. How you remove tips and stems depends of the size and age of the stem. The tips of new growth snap off easily when pinched, but there are also times when you'll need to cut larger or older stems.
Just a Pinch
Suckers develop in the crotch between the main stem of a tomato plant and the side branches. Pinch out the suckers by giving them a little squeeze between your thumb and forefinger. Pinching is convenient, after all, since you always have your fingers handy, and it leaves a clean break that heals quickly.
Cut It Out
The lower leaves on a tomato plant eventually turn yellow and die. These older stems don't pinch easily, so it's best to cut them out as soon as the color begins to fade. Trying to break them off can lead to accidentally stripping the lower part of the stem. Another time when you may want to cut rather than pinch is when older, thicker suckers need removing. You can cut out large suckers or pinch out the growth tip to keep them from growing. One advantage to leaving some short, leafy suckers is that they shade the fruit and help prevent sun scald.
Removing Growth Tips
When the plant grows to reach the top of its supporting cage, trellis or stake, pinch out the tip of the plant to stop the upward growth. This encourages the plant to concentrate its energy on fruit production rather than upward growth. You can also pinch out the tips of long side branches. You only need to remove a 2- to 4-inch tip to effectively stop the growth of a shoot.
Indeterminate tomato types are those that grow and produce fruit throughout the season. These tomato plants produce an abundance of suckers. If allowed to grow, the suckers will grow to produce suckers of their own. Suckers also produce tomatoes, and while it's fine to let an occasional sucker grow, leaving too many drains the plant of energy. The result is fewer and smaller tomatoes. If you want to leave a few suckers, the ones near the bottom of the plant are usually more productive. Suckers grow quickly, so pinch the plants a couple of times a week.
- Brooklyn Botanic Garden Tantalizing Tomatoes; Janet Marinelli, Editor
- National Gardening Association: Pruning Tomatoes
- Harvest to Table: How to Prune a Tomato
- North Carolina State University Cooperative Extension: Tomato Pruning
- Photo Credit BananaStock/BananaStock/Getty Images