Video: Tomato Pruning 101 • Tutorial with Niki Jabbour

It's easy to apply the basics of tomato pruning once you understand these simple principles.

Hi, I'm Nikki Jabbour. Today, I want to talk about pruning tomato plants. There are many reasons to prune tomatoes, but for me it's all about increasing yield and reducing diseases.

The approach to pruning depends on two things:

1) the types of tomatoes you're growing;

and
2) how you support the plants.

There are 2 main types of tomatoes:

1) DETERMINATE

and
2) INDETERMINATE.

DETERMINATE, or bush tomatoes, don't need to be pruned. The plants grow to a predetermined height and when they reach that height they set their flowers and fruits. If you remove the tomato suckers from determinate plants you're decreasing the amount of fruits you'll get.

INDETERMINATE tomatoes, or vining tomatoes, can grow tall, up to 6 or 7 feet tall (!) and are typically supported on stakes, trellises, or sturdy cages. Indeterminate plants benefit from pruning.

Pruning tomatoes is generally about removing suckers. These are the side shoots that grow from the angle where a leaf of a tomato plant meets the stem. Suckers do produce flowers and fruits, but allowing all the suckers (on indeterminate plants) to grow results in a dense, overgrown plant that's hard to support; and, due to lack of airflow, is more prone to diseases. And all of that shade in the middle of the plant can also slow down the ripening of the fruits.

So how do we prune tomato plants?

Well, that depends on how you like to support your plants.

I generally either use stakes or string, and allow two main stems to develop.

STEM #1 is the main stem.

STEM #2 is the sucker that develops just below the 1st flower cluster. This is typically a very vigorous sucker, and makes an ideal stem #2.

Once that sucker has developed, pinch out all the other suckers when small. They can be pinched by hand. If you wait too long, however, it's best to use clean garden snips or shears. I try to stay on top of pruning and take out new suckers every 7 to 10 days.

You don't have to stick to a 2-stem pruning system. You can allow 3, 4, or 5 stems to develop, as long as they're all supported and the subsequent suckers are then pinched out.

Gardeners who use heavy-duty tomato cages, tomato towers, or trellises often allow more than 2 stems to grow, as those plants are well supported.

One more type of pruning that I do to my tomato plants is to remove the lower leaves as the plants grow. The bottom leaves, which are often lying on the soil surface, are more prone to soilborne diseases, and removing them can slow the spread of these diseases or reduce their occurrence.

Happy Growing!