Talking about tomato terms for novice gardeners

Because tomatoes are a favorite veggie crop of home gardeners, we have a tendency to “talk tomatoes” a lot, sometimes leaving novice gardeners perplexed. Let me help translate some of this garden language.

Determinate & indeterminate

Most gardeners trellis, stake or cage their tomatoes to keep the plants upright and the fruit off the ground, saving space and discouraging fruit rot. It is easy to forget that tomato plants are vines that would naturally sprawl over the ground without support. Depending on the variety, vines have either a determinate or indeterminate growth habit.

Determinate tomatoes grow to a genetically predetermined length (or height if grown vertically.) When they stop growing in length, they continue to produce side branches. At some point, side growth ceases and flower clusters are produced at the end of each side branch. Some determinate plants are quite compact, such as many patio-type tomatoes, and can stand without support. Other varieties produce vines long enough to warrant caging or staking, but not trellising. Because they produce their fruit at the tips of side branches, they are not typically pruned.

Indeterminate tomatoes do not cease growing until stopped by cool temperatures and frost. To keep their rampant vines off the ground, substantial support is needed in the form of tall sturdy stakes, strong trellises or securely-fixed sizable cages. Indeterminate tomatoes are sometimes pruned to encourage earlier ripening and larger fruit.

Pruning

Pruning tomatoes does not involve getting out hand pruners or a chainsaw, but does involve snipping or pinching. The goal of pruning indeterminate tomatoes is to remove suckers on the lower third of the main stem of the plant. Suckers are the leafy shoots that develop in the nodes (the points where the main branches meet the main stem). Suckers do not produce flowers and the removal allows the plant to allocate more carbohydrates to the branches where the flowers and fruit are produced. This can result in an earlier crop and larger fruit.

Pruning is practiced in cool areas with a short frost-free season. In warm, humid regions with higher rainfall, pruning helps improve air circulation and discourage fungal disease problems. Pruning is not recommended in our region because we have hot, dry, sunny summers. Pruning removes growth that shades fruit and protects against sunscald. Also, excessive pruning predisposes tomatoes to fruit cracking and physiological leaf roll.

Caging, staking, trellising

Caging tomatoes involves using a homemade or commercially produced wire cage to provide support to tomato vines and keep them off the ground. Cages should be well anchored, especially in locations where strong summer winds are not unusual. Cages shorter than 5 feet can work well with many determinate tomato varieties. However, when indeterminate varieties are grown in cages, they are hard to keep upright and their fruit is difficult to harvest.

When staking tomatoes, plants are pruned to one or two main shoots, and tied to a sturdy stake as tall as the vines will grow. Some gardeners use 2-by-2 lumber for making stakes and others use metal fence posts. Stakes are secured by driving them 8 to 12 inches into the ground.

Trellising is increasingly popular, because many gardeners grow more than just a couple of tomato plants. Sturdy stakes are still employed, but the plants are placed between the stakes and then garden wire or twine is woven between the stakes as the plants grow. For more information on trellising, go to bit.ly/trellis_tomato.

This story was originally published January 29, 2017 at 7:55 AM with the headline "Talking about tomato terms for novice gardeners."