Training Tomatoes

Pruned Green Tomatoes
Pruned Green Tomatoes

Every year I look forward to the day in June when I go to the garden and notice that my tomato plants are about to fall over and are in need of pruning and tying. It is hard to explain my sense of anticipation. Most people would dread the prospect of spending hours meticulously scrutinizing plants. Besides, it takes a good five minutes of hand-scrubbing to get rid of that nasty green stain from pruning the shoots. And for what gain? It is debatable whether yields are increased by all the hard effort. (They may even be decreased.)

I guess it has to do with intimacy. There is nothing like getting to know each individual plant from root to stem to leaf to fruit. Tomatoes are fascinating creatures whose ability to produce and reproduce never ceases to amaze me.

I first learned to prune and trellis tomatoes at Live Power Community Farm, a biodynamic vegetable CSA farm in Covelo, California. The technique practiced had been handed down from the infamous organic gardening mentor, Alan Chadwick. The other farm apprentices and I would spend hours keeping those tomatoes in line. While exploring and manipulating the anatomy of tomato plants we would also discuss the anatomy of our own emerging social and sexual lives. Those were the days!

These days I am mostly on my own in the garden, but I still enjoy the hours spent meditatively working with tomato plants.

The idea behind pruning and tying tomato plants is quite simple. As with other pruning systems, by controlling the vegetative growth of the plant, more energy is channeled into fruit development and maturation. More space for light and air is created. Plants are less unruly, with less fallen plants, disease, and rotting, while fruits are more visible and accessible. Fruits often tend to be earlier and ripen more evenly throughout the season.

Before attempting to train tomatoes you must be certain that your varieties are indeterminate. Determinate tomatoes usually terminate leaf and shoot growth with a single fruit bract, thus creating a low-growing, bushing habit not suitable for pruning. Most seed catalogues will note whether the tomato varieties they sell are determinate or indeterminate.

Studying tomato plants is a great way to learn about plant development. If you carefully examine a young tomato stem, you will notice leaves and, after time, flower bracts jutting out. At the vertices between each main stem and outgrowing leaf stem is a growing point. From this point a shoot usually emerges.

Each shoot has the potential to grow into yet another main stem with its own leaves, flower bracts, and yes, of course, more shoots. Most plants follow some variation of this growth pattern. The fruiting habit of tomatoes is also somewhat predictable. Once the first fruit bract emerges, another will usually follow after every set of three leaves.

Since, unlike their determinate cousins, the stems of indeterminate plants keep growing regardless of fruit production, exponential vegetative growth results, creating the jungle-like plants many are familiar with. However, it is this same vining habit that enables tomatoes to be trained.

By de-suckering the young shoots off the main stem, one can contain the spreading nature of the plant and allow one, two, or even three main stems (often called “leaders”) to keep growing. Usually the shoot that emerges from the leaf right below the fruit bracts are the most vigorous and need to be removed promptly. I will often choose the shoot below the first fruit bract as my secondary leader.

As you spend more time with your tomatoes you will start to notice their crazy botanical antics. Tomato plants seem to have the potential to grow roots and stems from just about any nook and cranny of the plant. Keep a watchful eye for suckers emerging from below ground. (These can also be good, vigorous candidates for additional leaders.)

You may even find that some fruit bracts themselves will start developing their own infinitely reproducing stems. Also, any stem that contacts the soil will start to root out–a fact that can be used to advantage in certain circumstances.

I will usually train my tomatoes about two or three times a month. I go through picking off any side shoots from my leaders, exploring from top to bottom and gently tying my stem to whatever trellis I am using. By August my tomatoes are often taller than the fence and I start pruning back the tops and getting a little less thorough with my overall pruning.

As with all gardening, it is much easier to learn by seeing and doing than reading. If I have inspired anyone to attempt training his or her tomatoes, I welcome you to come see my own system in action.

Happy gardening!

Editor’s Note: We enjoyed the tomato pictured below on June 21st, the Summer Solstice. In our climate zone, to have ripe tomatoes by mid to late July is considered early! Jonathan got a big jump on the season using cold frames. See his posts on Cold Frame Gardening.

June Tomato
June Tomato