Should You Prune Out Tomato Suckers? What You Need to Know (2024)

Tomato plant suckers or side shoots are the growths that appear in the junction between the stem and a branch of a tomato plant call the "axil." When left to grow, tomato plant suckers will become another main stem with branches, flowers, fruit, and even more suckers of their own. Read on to learn how it benefits the health of your plant to remove these growths.

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Why Pruning Is Recommended

Pruning tomato suckers is often recommended because the resulting new stem is competing for nutrients with the original plant. Your plant may have more fruit if you let the suckers grow, but the tomatoes will be smaller, and the plant will be more cumbersome, requiring a lot of effort to stake as the summer progresses. Pruning tomato suckers also does the following:

Makes your plants more manageable and more robust at the same time
Improves airflow of indeterminate tomato plants to reduce disease, as leaves dry faster after the rain and makes them less susceptible to diseases that thrive in prolonged moisture
Makes it easier to spot pests that are camouflaged in a thick canopy of leaves
Speeds up fruit ripening

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How to Prune Tomato Suckers

The earlier you prune the tomato suckers, the easier it is. Here's how:

Snap off any suckers at the stem with bare hands when they are small - about 1/2 inch.
Cut stems thicker than a pencil with pruning shears to prevent damage to the plant.
Prune leaves near the base of the plant to prevent soil-borne diseases that can splash onto leaves.
Trim suckers and unnecessary flowers on a weekly basis during peak growing season.
Clean the shears with an alcohol wipe before pruning different plants to avoid spreading any disease.

If the plant has a strong main stem, prune the majority of suckers. Not all suckers need to be removed from mature plants.Be careful not to over-prune—some leaves are needed to protect the fruit from sunscald, particularly in the hot south.

Types of Tomatoes That Need Pruning

Pruning tomato suckers is not a must and many gardeners don’t bother with tomato pruning at all. Some varieties of tomatoes will do better when pruned, while it matters less with others. In addition, pruning is also a factor in tomatoes that are categorized as either indeterminate or determinate, depending on their growth habit.

Tip

Here's how you tell the difference between indeterminate and determinate tomatoes:

Indeterminate tomato plants are more vine-like, such as cherry tomatoes, Beefsteak, and heirloom tomatoes.
Determinate tomato plants have a “bushy growth with side shoots and include Roma and Celebrity tomatoes.

Indeterminate

Since indeterminate tomato plants can get extremely large and will keep producing tomatoes all season, they can handle some pruning. Pruning indeterminate tomatoes also allows more space for extra plants in the garden. If you leave all the suckers to grow, your plants will become heavy and out of control. Keep in mind, though, that if you remove all of the suckers, the plant will be more compact and yield fewer tomatoes throughout the season, but they'll typically be bigger fruits.

Determinate

In contrast, determinate varieties of tomatoes don’t require any pruning at all. These tomato plants are naturally more compact; they're genetically programmed to reach a certain height and stop growing. They don’t usually set their fruit until the branches are fully grown, and then they set their fruit within a pretty short window. Since no new fruit will develop after pruning, nothing is gained by trimming off the tomato suckers on these types of plants.

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When to Prune Tomato Suckers

Pruning can take place throughout the growing season. At planting time, remove the lower leaves and bury the stem deeply in the soil. Roots will grow along the stem, helping to add stability to the plant. As the plant grows throughout the season, remove leafy suckers beneath the first fruit cluster so they won't slow the development of the fruit.

Pruning late in the season is a race to ripen fruit before the first frost. About four weeks before your area's expected first frost, remove the growing tip of each main stem. Called "topping," this pruning causes plants to stop flowering and directs all sugars into fruits to speed ripening.

Practice of Pruning Tomatoes

Tomato pruning is more trial and error than precision, so look at it as a learning experience. When you first start pruning, do less rather than more. If you grow the same varieties year after year, you’ll get a good feel for how they respond to pruning.