Pruning Tomatoes

There are probably as many different opinions on tomato pruning as there are varieties of tomatoes. The two basics everyone agrees on are do prune indeterminate plants and don't prune determinate plants. To define terms, indeterminate tomatoes are varieties such as cherry and beefsteak that will continue growing and producing fruit until the end of season when they are killed by cold weather. Determinate tomatoes are varieties such as Roma and Homestead that will only grow to a predetermined height and produce and ripen almost all of their fruit at once.

Indeterminate plants grow quickly and recover from pruning. If they are allowed to grow without any control, they will produce masses of branches that block light and airflow and draw too heavily on available nutrients. Pruning will limit the number of fruit, while producing larger, healthier tomatoes.

Determinate plants won't have time to recover from pruning and won't really benefit in the long run.

Among the pruning techniques favored by growers, hard pruning is the most severe, reducing the plants to two main stems. This is most common in greenhouse growing, where the open form of the plants allow much needed airflow and ease in picking fruit.

I prefer to keep pruning down to a modest level.

The photos above show a plant before and after. One of the most important areas to prune is the lower eight to twelve inches of the plant. Any leaves or branches that touch the ground run the risk of picking up early wilt, insects or other problems that can become serious. I use my gardening knife to prune this growth. Increased airflow and sunlight reaching the soil and lower trunks help keep the whole garden healthier.

These cherry tomato plants will still produce plenty of fruit, without any touching the ground. Tomatoes that rest on the damp soil have a much greater risk of insect damage, rot and being overlooked when picking (personal experience).

I also prune the foliage from the lower eight inches or so of determinate plants for these same reasons. I don't believe that those lower branches would have been productive anyway.

Hard pruning of indeterminate plants involves removing suckers, the new branches that sprout from the node where a leaf stem joins the trunk. An alternative to hard pruning is to space plants several feet apart and apply plant food generously.

Proper pruning technique takes study and experimentation, and it's best not to get carried away. I recommend watching YouTube videos and reading how-to articles in books and online in order to gain an understanding of the hows and whys involved. It's best to know your goal in pruning and plan accordingly. For me, it's all about doing the minimum necessary. I still cringe a little every time I clip a sucker, knowing that it might have produced a few more tomatoes.

Stephen