Here's what you need to know.

Advertisement

If you fastidiously check on your tomato plants more than once a day, you probably already know that pruning can be an important part of your plant care routine. Pruning tomato plants is an optional, yet recommended, technique that some gardeners use to keep plants tidy, manipulate fruit size, and even hasten ripening. Before we talk about how to prune tomato plants, let's talk about why and which types of tomato plants you should prune.

Determinate vs. Indeterminate Tomatoes 

When you purchase a tomato plant from a nursery, the container label should identify the plant as either determinate or indeterminate.

Determinate tomato varieties are often referred to as "bush" tomatoes because they do not continue extending in length throughout the season. Growing a determinate variety, such as Roma, is practical when you want a lot of tomatoes at one time for freezing, canning, or making sauces. Determinate tomatoes do not need to be pruned; because they develop all of their fruit at one time, pruning may cause you to sacrifice tomatoes for no reason.

Indeterminate tomato varieties, such as Beefsteak, Brandywine, and many cherry types, are vining plants that continue to extend in length and produce fruit throughout the growing season. Pruning indeterminates can help to keep the huge vines in control, and it encourages the plants to produce several large tomatoes instead of lots of foliage and many smaller tomatoes.

Improved Airflow

Fewer leaves mean the plant is less dense, which allows for more air to flow among the stems. A well-pruned plant will also dry faster after a rain, so they are less susceptible to the diseases that develop from prolonged moisture. Fewer leaves also make it easier to spot insect pests that like to hide in thick canopies leaves.

Larger Size

Pruning at the right time directs energy toward creating and ripening fruit instead of making more leaves. Overall, you will probably have fewer fruit on a pruned plant, but it will be bigger. And, since pruned plants can be put a bit closer together in the ground because the growth is so vertical, you can have more plants in your home garden. When a plant has fewer leaves and less fruit to take care of, that fruit ripens faster. This can help in short season climates, where getting a tomato harvest is often a race against time, thanks to early fall frosts.

Prune a tomato plant
Credit: Melinda Podor/Getty Images

How To Prune Tomatoes 

Pruning is really a simple process. Look for the tomato "suckers," which are the side shoots that grow in the "V" space between the main stem and the branches on your plant. If left alone, these suckers will eventually grow into full-sized branches-adding lots of foliage and, eventually, a few fruits. This will also result in a tomato plant that quickly outgrows its space in the garden.

To prune, simply remove the suckers. If under two inches long, you can pinch the sucker off with your fingers, but use a pair of clean gardening pruners for larger ones. Always disinfect your pruners as you move from one plant to another to prevent the spread of disease. Keep an eye on your tomato plants so you can remove suckers as they emerge. Removing large amounts of foliage at one time can stress the plant.

Stake up or remove any branches that are low-hanging or touching the ground; foliage that is touching the ground can be susceptible to bacteria, fungi, and viral infections that can spread through the rest of the plant.