Tomatoes are some of the easiest plants to grow in the garden. They germinate readily, grow quickly, and can provide delicious produce all growing season. They’re perfect for beginners masters alike. As easy as tomatoes are to grow, there’s a little trick that separates the beginner tomato gardeners from the masters: pruning. Pruning your tomato plants can seem daunting at first. After all, why would you want to chop up the plants that you’re trying to grow?! As it happens, pruning your tomato plants can actually increase your harvest, if done correctly.

Why Prune Tomato Plants?

Pruning tomato plants is a good idea for a couple different reasons.

1. Encourage the tomato plant to send more nutrients to the fruit.
   • The whole reason you’re growing tomato plants is to grow tomatoes, right? Well then, you want to encourage fruit growth rather than leaf growth. Pruning tells the plant to focus on growing more and better tomatoes rather than more stems and leaves.
2. Disease Prevention
   • Tomato plants are often very susceptible to diseases like molds and fungi. Even hybrids that have been bred for resistances can use a little help. Pruning can help limit leaf contact with the ground. This, in turn, limits the plant’s exposure to dangerous organisms that can kill your plants and ruin your harvest.

What Tomato Plants to Prune?

There are lots of different varieties of tomatoes out there. Cherry tomatoes, beefsteak tomatoes, sauce tomatoes make up only a few categories we can divide tomatoes into. No matter the variety, all tomato plants can be broken down into two categories: determinants (bush) and indeterminants (vine).

This distinction is important when deciding whether your tomato plants should be pruned for the optimal harvest.

Bush Tomato Plants (Determinant)

Determinant or bush tomato plants don’t need much, if any, pruning. These plants have been selectively bred to stop growing at a certain height (usually about 2 feet). After which, they send all their nutrients to producing fruit and less on growing leaves and branches. This means, less work for you! You may decide to cut away some of the lower branches on determinant tomatoes to limit contact with the ground. But that’s all you’ll need to prune on determinant tomato plants.

Vining Tomato Plants (Indeterminant)

Meanwhile, indeterminant or vine tomato plants benefit greatly from pruning. These plants don’t have any DNA code telling them to stop growing when they grow to a certain height. So, in addition to protecting them from soil diseases, they also need a little help from their gardener to keep them from getting out of control. That’s where pruning comes in.

When Should You Prune Your Tomato Plants?

Prune your tomato plants when they are about a foot tall. Depending on when you plant your tomatoes and which variety you decide to grow, this may be anywhere from May to August. At about a foot tall, your tomato plants should have at least three rows of leaf branches.

How to Prune Tomato Plants

Pruning for disease prevention and pruning to keep your tomato plants from getting out of control require different methods. Let’s take a look.

Bottom Leaves

When pruning your tomato plants for disease control, you want to take off the bottom leaves. This is an easy decision if you have leaf branches that are already touching the ground. But how far up do you trim?

Before you prune, keep in mind how big your tomato plant is. At only a foot tall, it probably only has three layers of leaf branches. In this case, only cut away the bottom branch(es). You want to leave at least 2/3rds of the plant intact.

When the tomato plant is older and has more leaves and leaf branches, you can get away with pruning all the leaf branches beneath the first cluster of fruit. Just don’t cut leaf branches any higher than that first cluster. Not only do leaves provide the plant with nutrients, they also shield young tomatoes from sun scalding by providing shade.

Tomato Suckers

As the plant grows, your tomato plant will grow tiny new branches. These new branches are called “suckers” and they grow from nodes between the stem and a leaf branch. These suckers can be safely pruned away without causing the tomato plant any stress. In fact, leaving suckers in place is what causes the plant to literally branch out and create new stems.

New stems will have to grow several inches before they begin to produce fruit clusters of their own. During that time, the new stem is drawing nutrients that are better used to grow the main stem and nourish any fruit that are forming.

When suckers are small, no garden sheers are required to eliminate the nascent branch. You can use your thumb and forefinger to pluck the sucker from the branching node. This is referred to as “pinching”.

You may decide to leave a sucker in place, especially near the base of the plant. This is a gardener’s prerogative and your decision to make. Splitting the main stem into two or even three can create more fruit in the long run. If you have a longer growing season, or a long time before autumn yet, it may be a good idea to let one or two suckers become branches. After a short growing period, they’ll add to the main stem’s fruit clusters. with clusters of their own.

A Useful Guide to Pruning Tomatoes

It can be difficult to know what you’re looking at when your out in your garden. The wind blows the tomato branches around. The serrated edges of your tomato leaves want to hold hands with each other. It can be tough to figure out what’s what out there in the wild.

So here’s an easy guide to help you out! Compare this to what you see outside, and you should have a good enough idea what you’re looking at.

Pruning Tomatoes in the Autumn for Better End of Season Tomato Growth

Indeterminate tomatoes continue to grow stems and leaves even as the growing season draws to a close. This can be a problem if you still have fruit on the vine that hasn’t ripened yet. You can encourage your green tomatoes to ripen by pruning the main stem of your plant at the top above the last fruiting cluster. Pruning the main stem forces the plant to send its energy to the unripe tomatoes rather than to branches or leaves. This technique is called “tomato topping.”

If you decided to leave one or two suckers to create branches of their own, you’ll want to clip those branches as well. Otherwise those branches will take over as the new main stem and continue to use up nutrients you need for your tomatoes to finish ripening. [That’s not to say all green tomatoes are bad! Learn how to deal with green tomatoes.]

Avoiding Over-Pruning

You should never prune more than 2/3rds of a tomato plant. After all, the tomato plant needs its leaves to draw nutrients from the sun and the air. If it doesn’t get enough light, the tomato plant will die.

Also, don’t clip the main stem unless your growing season is coming to an end. If you do prune your main stem before autumn, or if damage occurs to the main stem in a summer storm, you should leave a sucker near the top of the plant to mature. This will allow the new sucker to become the main stem and continue to produce clusters of fruit that can ripen before frost falls.

Prune and Prosper!

Pruning your tomatoes is a great way to

• Deter diseases that may splash up from the soil,
• Improve your overall tomato harvest, and
• Limit end of season green tomatoes.

Remember:

• Never prune more than 2/3rds of your tomato leaves.
• Avoid sun scalding by never pruning leaf stems above the first cluster of tomatoes.
• Don’t prune your tomato plant’s main stem unless your growing season is ending.
• Suckers can be allowed to grow early in the season to become full branches and produce fruit clusters.
• Not every sucker should become a branch.

By deciding where you want the tomato to send its nutrients, you control the outcome of your harvest and the shape of your tomato plants. It’s relatively simple to watch for new suckers to appear and deal with them as you see fit. It’s nurture vs nature for the win in your garden!