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A Guide to Pruning Tomato Plants

Pruning tomato plants is completely optional. There is no law in gardening that mandates that the pruning of all tomato plants. Although there certainly are advantages to pruning tomatoes, there are some disadvantages as well. This article will address the pros and cons of pruning tomatoes, as well as look into possible compromises between the two sides.

But first, an introduction to those who are not familiar with what pruning is all about. Tomato plants are extremely vigorous plants when it comes to growing. Although the little transplants you put into the garden in April or May do not look like anything threatening, they turn into beasts once the heat sets in. That’s when their growth rates start doubling and the plants themselves turn into monsters. The primary vehicle by which tomato plants get big is “suckers”, those shoots that spawn between the main stems of a tomato plant. Those shoots will grow big and turn into a major stem themselves, from which additional shoots can spawn. So for you math savvies out there, we can say that tomato plants will grow exponentially if left unattended.

So what’s so bad about these suckers—even if they do make the plants huge won’t that mean more fruit production? Yes- they will make the plants produce more fruits, but they will also cause the plant to sprawl on the ground like a wild bush. That’s because when the matured suckers start carrying fruits on them, the main stem can no longer bear the weight of the fruits, causing it to hump downward along with all its branches, like a willow tree. The suckers will then continue to grow along the surface of the ground, and the whole thing can turn into a tangled mess...

There are also other problems associated with unattended sprawling tomato plants than just being an eyesore in the garden. Sometimes, when the weight of the fruit is too heavy for the branch to support, the branch carrying the fruit might snap, dropping all of the fruits. But insects and disease from the dirt will cause most of the problems with sprawling tomato plants. Insects can chew up the fruits before they even ripen, and viruses can eventually kill off the entire plant. That is definitely not the result you want to have after working so hard to feed and water your plant to turn it into a giant in the first place.

Pruning tomato plants involves pinching the suckers soon after they appear, but not until you have visualized how you want your plant to look—in other words architect its structure. It’s sort of like ice sculpting- carving away the unwanted pieces to get figure you desire. Just remember that each sucker you leave on will turn into another branch stem. The pruning process can simply be done with your hands, but if you use any sort of utensils be sure to sterilize them first.

Proper pruning has many benefits, especially for those growers located in the regions with shorter growing seasons. Pruning the leaves off of a plant maximizes the amount of photosynthesized sugar that goes into fruit formation. This means an overall increase in the quality of the fruits. Compared to non-pruned tomatoes, pruned plants will be slightly bigger and better tasting. They will also be formed quicker because they’re the only parts of the plant that are growing. But unfortunately, all these benefits do not come for free. They come at the cost of decreased overall fruit production, because there are less leaves remaining on the plant to photosynthesize sugar (to form fruits) in the long run. Determinate tomato varieties should not be pruned at all, because they grow to a fixed size and produce a fixed amount of fruits. Pruning is most effective near the end of the season, where you want to pinch off all newly formed suckers and the main growing tip to expedite the formation and ripening of the remaining fruits.

Alas, if you choose to prune, it can be the most labor intensive process in the art of growing tomatoes, especially for big indeterminate varieties like Cherokee Purple and some Beefsteak varieties. During the heat of the summer, a whole heaping lot of suckers need to be removed. But depending on conditions, the rewards of pruning tomatoes may be well worth the effort.

Here are some general guidelines on pruning. A properly pruned tomato plant should have enough leaves remaining to cover and protect its fruits from sun scalds. This means that for bigger fruited varieties, you should prune less so that more leaves could form. Thus pruning will take practice and experience. Also, do not prune when the plant is wet, as that’s when it is most vulnerable to infections.

With all these talks about pruning and not pruning, there must be a tradeoff of something in between. And there is- in using tomato cages rather than conventional stakes for support. Tomato cages will provide a lot more support to a growing plant, allowing it to get by standing with more stems. Growing a tomato plant supported with a cage with slight pruning, the plant will require more space than fully pruned plants, but will less messy than non-pruned plants. In fact, having towers of tall, compact tomato plants in your garden could be quite a formidable sight in your garden, depending on your taste of aesthetics.

You can build your own tomato cages or buy them from the store. Whatever you do, don’t use those silly wired cones sold in the department stores. If you have the time, you can build tomato cages from fencing wire or from PVC pipes. If not, there are plenty of sources both offline and online.

Again, the decision to prune your tomatoes is completely up to you. It’s absolutely fine to leave your tomatoes sprawling, as that’s how native tomato plants grow anyways. But if you choose to do that, be sure to carpet the growing area with mulching or a piece of plastic to prevent diseases and insects. There are no specific, definite guidelines with regards to pruning tomatoes. Some people live by it, most prune a little, and some don’t prune at tall. What matters is your own personal taste.