Tomato plants can be determinate or indeterminate, and the type of plant will dictate how you should prune.

Determinate tomato plants will stop growing at a certain point and direct all of their energy into producing more leaves and fruit. They produce a large crop of tomatoes that mature all at once. Most beefsteak and sandwich tomatoes are determinate varieties.

Indeterminate tomato plants have a more vining, vigorous habit. They produce tomatoes that ripen over a period of several weeks.

Pruning determinate tomatoes. Remove all blossoms until the plant is well established in the garden. This helps the plant to direct its energy into growing stronger and larger, instead of producing fruit too early. Next, remove the suckers as they appear. They have to grow quite long before they will produce fruit, and they direct needed energy away from the main stem of the plant. Try to check your tomato plants for suckers at least once a week. Near the end of the growing season, you’ll need to “top” the plant. Topping means pinching off the growing tips of the plant. It’s necessary to do this so that the remaining fruits have a chance to ripen. If you want very large tomatoes, you can remove all but one blossom from each cluster. The plant will direct all of the energy from that stem into a single tomato.

Pruning indeterminate tomatoes. Pruning indeterminate tomatoes is more complex, but it is a necessary task. Indeterminate tomato plants will form as many as ten vines if left on their own. This means that the plant ends up lying on the ground, an easy target for sunscald, disease and pests. Remove all blossoms until the plant is between 12 and 18 inches tall. Next, remove all suckers below the first fruit cluster. You can continue to remove all suckers if you want just a single vine. However, most people prefer to let two or three vines grow. To do this, let a second stem grow just above the first fruit cluster. If you would like a third stem, let the sucker just above this stem grow, also.

Keeping the side stems close to the first fruit cluster ensures that they will be strong and have enough energy to produce abundant fruit. Some people choose not to prune their tomatoes at all. The fruit that is formed on unpruned plants is generally smaller and not as flavorful as from pruned plants, although it is more plentiful.

Keep tomato plants off the ground. Give plants room. Never prune or tie plants when the leaves are wet.

Here is a photo of where to locate a sucker on your tomato plant. They always grow between the main stem and a side stem. Simply hold the sucker and break off.

This entry was posted on Monday, March 3rd, 2008 at 5:45 am and is filed under Growing Tips. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.