Many gardeners prune tomato plants to improve the quality of the fruit, encourage better fruit production, speed up the ripening process, keep the plants from growing too large, and even manipulate the plant’s ripe fruit size. However, plenty of gardeners do not prune tomato plants since it is not required, so you can experiment to see what works best for you.

Read on to find out how to prune a tomato plant for a better harvest.

Why You Should Prune Tomato Plants

Pruning indeterminate tomato plants helps direct the plant’s energy towards producing fruit rather than producing more foliage. Removing suckers and yellowed leaves also encourages larger fruit, better airflow, fewer diseases, and for container-grown tomatoes, better size. Here’s why.

Larger Fruit

Unpruned foliage eventually grows into new branches that form fruit, but experienced growers advise pruning to produce larger fruit earlier in the season.

Better Airflow

When a tomato plant is pruned correctly, all of the foliage receives adequate sunlight, and the plant can photosynthesize more efficiently, boosting growth and fruit production. When leaves are forced into shade, such as when bushy plants are on the ground, the amount of sugar they produce is reduced, and growth is impeded.

Fewer Diseases

If you have fungal issues in your garden, pruning can solve the problem of tomato plants lying on the ground or leaves coming into contact with the soil. Pruning the plants may discourage the development of soil-borne fungal diseases in the plant.

Controlling Size

Pruning is a good way to control the size of tomato plants growing in containers. Otherwise, a vigorous tomato vine can outgrow its pot. Ideally, choose compact tomato varieties for planting in containers to minimize pruning.

Pruning Indeterminate vs. Determinate Tomatoes

Not all types of tomatoes need to be pruned. Learning whether you have determinate or indeterminate tomatoes can help you decide.

Determinate Tomatoes

Determinate tomatoes, often called bush tomatoes, do not need pruning. These varieties grow to a fixed mature size, usually around 4 to 5 feet. These tomatoes typically ripen all of their fruit within a few weeks, so pruning doesn’t provide much benefit.

Indeterminate Tomatoes

Pruning is encouraged if you’re growing indeterminate tomatoes, which produce fruit regularly throughout the season. Indeterminate tomatoes continue to grow throughout the season, eventually becoming very large vines that could reach up to 20 feet in length.

Pruning controls the vine’s size and encourages larger tomatoes instead of more foliage and smaller tomatoes. Many of the most popular tomatoes, including cherry tomatoes, heirloom tomatoes, and cultivars such as ‘Big Boy,’ ‘Beefsteak,’ and ‘Brandywine,’ are indeterminate.

When to Prune Tomato Plants

There are early-season ripening, midseason ripening, and late-season ripening tomatoes. Regardless of the type of tomato you have, the time to prune tomato plants is when you first see the flowers opening. The timing may be around June or July. Continue pruning once or twice more every two weeks until harvest time.1

It’s also best to prune in the early morning on a dry day so wounds can easily heal.