Hand Pruning A Tomato Plant
prune tomato
(Image credit: Delpixart)

Sometimes the tomato plants in our gardens get so large and so unwieldy that you can't help but wonder, "Should I prune my tomato plants?" This question is quickly followed by, "Exactly how do I prune tomato plants?" Let's look at these two questions.

Should I Prune My Tomato Plants?

The answer to this question is actually a personal one. Some people assert firmly that pruning tomato suckers improves the production and health of a plant. Others claim that pruning tomato suckers damages the plant unnecessarily, opening it up to disease and doing nothing to actually help.

So, scientifically speaking, who is right? A study at Iowa State University (PDF) published in 2000 showed that pruning tomato suckers sometimes made a difference and sometimes did not in terms of the size the fruit. And, whether pruning the tomatoes improved the fruit just depended on luck as to whether or not the tomato plant developed disease because of the pruning. But the study did not find that pruning tomato suckers ever helped with the yield of the plant.

But, on an anecdotal level, a great many Master Gardeners recommend the practice of pruning tomato plants. One has to wonder if these people who work with plants all the time and are considered the ultimate experts in their field know something that the scientific types have missed.

So, as stated, the decision to prune tomato plants is one that you will have to make with your own best judgment.

How to Prune Tomato Plants?

If you have decided to try tomato plant pruning, you need to make sure that you do it the correct way to help reduce the chances of disease.

  1. You want to start pruning tomato plants a when they get to be about 1 - 2 feet (30-60 cm.) tall. Any smaller than this, and the plant may not recover from the shock of being pruned.
  2. By the time your tomato plant gets to be this size, the plant will have branches coming off the main stem. Where these branches meet, you will see and additional branch growing. This is called a tomato sucker.
  3. Using a sharp, clean pair of pruning shears, snip these small sucker branches off.
  4. The best time to prune tomato plants is in the early morning on a dry day. This will allow for the wounds from the pruning to heal cleanly and will reduce the chances of the plant being infected by disease.
  5. If you choose to prune tomato plants, make sure that you use watering methods that water the tomato plants at the soil level (like soaker hoses) rather than from above (like sprinklers). This will prevent the splashing of soil up onto the tomato plant and the tomato plants wounds.

Your answer to the question, "Should I prune my tomato plants?" is your own, but now you have some additional information on why and how to prune tomato plants.

Looking for additional tips on growing perfect tomatoes? Download our FREE Tomato Growing Guide and learn how to grow delicious tomatoes.

Heather Rhoades
Founder of Gardening Know How

Heather Rhoades founded Gardening Know How in 2007. She holds degrees from Cleveland State University and Northern Kentucky University. She is an avid gardener with a passion for community, and is a recipient of the Master Gardeners of Ohio Lifetime Achievement Award.