How to Prune Tomato Plants – A Simple, Straightforward Guide

The conversations around pruning tomato plants can be dizzying! Some gardeners say definitely do, while others say don’t bother. And the methods vary as well: remove entire branches, cut just the tips of branches, prune at certain times, prune throughout the season, and so on. This can all leave you wondering not only how to prune tomato plants, but whether it’s worth doing in the first place.

To help you untangle all of the techniques and opinions, here is a straightforward guide to tomato pruning.

How to Prune Tomato Plants

Should tomato plants be pruned?

Although not technically necessary, pruning helps keep tomato plants tidy and healthy and stimulates fruit growth.

Reducing the foliage on a plant improves airflow, thus reducing the likelihood of diseases that often develop in the presence of excess moisture. It also directs the plant’s energy away from leaf growth and toward larger fruit production, which is really the whole point of planting tomatoes in the first place!

Before you begin trimming your tomato plants, it’s important to know which type you have.

• Determinate varieties stop growing at a certain height, have a bushier habit, and produce fruit earlier but in a specific timeframe. These should only receive minimal pruning.
• Indeterminate varieties, on the other hand, will continue growing and producing fruit until frost. Because of their indefinite growth, they can be pruned rather vigorously.

When to prune tomato plants

Tomato pruning should occur in stages throughout the growing season. Below is a step-by-step list to walk you through the process, with a few more details in the sections that follow.

1. When planting seedlings out in the home garden, pinch or cut off any lower leaves that may come in contact with the soil. You may need to repeat this step later, as branches that initially seem high enough sometimes droop as they grow. Always keep the base of the plant trimmed.
2. Once the plants grow taller than a foot, begin removing suckers and any diseased or otherwise damaged branches. This process will continue through the end of the season, especially for indeterminate types.
3. About four weeks before the first frost, remove the growing tip of each main stem (indeterminate plants only). This signals the plant to stop flowering and instead finish ripening all of the fruit already on the vine. Even if they don’t ripen before frost, any green tomatoes you bring inside after “topping” the plant should fully ripen on the counter.

If your tomato plants are already large and wild, don’t worry! Remove all of the leaves about 12 to 18 inches off the ground and lower, then move on to step two.

Tomato pruning tools

If you prune your tomatoes regularly when the suckers are small, all you need is your fingernails to pinch them.

But, if you forget or don’t have time and you find yourself with long, thick suckers, you’ll need to use pruning shears to make a clean cut and ensure you don’t damage your tomato plant.

Learn more about growing tomatoes.

How to remove tomato suckers

Before pruning suckers, identify the lowest cluster of flowers (or fruit, if your plants are already mature), then the leaf directly under it. Start by pruning only below this point of reference. If you remove too much foliage above this point, you risk exposing the fruit to too much sun, which can result in sunscald.

Now that you know where to prune, you need to know what you’re actually pruning! A sucker is the new growth that appears between the main stem and a leaf. If you catch them when they’re small enough, you can simply pinch off the shoot at the base with your fingers. A sharp knife or pruner will help with larger suckers.

Many gardeners remove all suckers as they appear, even above the lowest/first flower cluster. If you choose to go this route, make sure that the remaining foliage will sufficiently shade all of the fruit, especially if you live in a hot, southern region. A good way to prune higher up without inviting sun scald is to pinch off only the leaflets at the end of each sucker, leaving the two base leaflets to shade the fruit.

Because indeterminate tomato plants continue to grow indefinitely, you will need to check regularly for new suckers. As you do this, look also for any diseased or otherwise damaged leaves and any that touch the ground, and remove these as well.

How to keep tomato plants from growing too tall

What if you planted an indeterminate variety (especially cherry tomatoes) but don’t want your tomato plants to grow above a certain height? To keep tomato plants from growing beyond your reach or above the height of their supports, simply pinch off the growing tip once the plant reaches the desired height.

In some cases, this will help you get larger tomatoes, as the plant’s energy goes into fewer tomatoes.

This is also a great way to encourage late-season tomatoes to ripen before frost (see “When to prune tomato plants,” above).

What to do with pruned suckers and leaves

Never leave tomato clippings in the garden! Leaving clippings at the base of the plants can contribute to the spread of tomato diseases such as tomato blight, so make sure to collect all of the leaves and suckers and dump them on the weed pile.

If your plants are healthy and you’re pruning early in the season, the suckers could easily be new tomato starts that will give you delicious tomatoes in late summer.

Another good practice to prevent disease spread is to clean your knife or pruners with an alcohol-based disinfectant after each use.

Learn How To Prune Other Plants

• How to prune hibiscus
• How to prune roses
• How to prune mums
• How to prune hydrangeas

Tomato pruning FAQs

Once you untangle all of the advice available about pruning tomatoes, the process itself is really pretty simple. I hope this article has granted you some clarity and thus confidence to prune your tomato plants for a tidier garden and a bountiful tomato harvest. Happy growing!

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