How to Prune Suckers from Tomato Plants

How you prune a tomato plant affects production and fruit size.

Deciding when and how to remove suckers from tomato plants often causes confusion for gardeners, as there are positive reasons for removing suckers and allowing them to grow. Some gardeners prefer an abundance of fruit, even if the size is reduced. Others prefer fewer fruit that are larger. How you prune suckers from the plant affects both fruit production and size.

Instructions

1. Decide whether an abundance of fruit or fruit size is more important to you. Pruning the suckers from the main plant reduces the amount of fruit, but generally increases the size by an ounce or two. Those allowed to grow freely without pruning produce more fruit, but size is reduced.

2. Determine if your tomato plants are determinate varieties that reach a certain height and cease growing, semi-determinate (slightly larger) or if they are indeterminate plants that continue to grow in height and width throughout the season. Check the plant identification label for this information. If you are unsure, refer to the resource section for common varieties.

3. Prune suckers from indeterminate varieties. Determinate and semi-determinate plants are generally short and compact and produce fruit on the ends of each branch. Determinate and semi-determinate varieties do not benefit from major pruning, but may be pruned sparingly to maintain shape.

4. Pinch out suckers (the young shoots that appear in the crotch above a leaf stem) when they are 2 to 3 inches long. Allow two or three suckers to grow from the base of the tomato plant, as these will form main stems that produce blossoms and set fruit.

5. Repeat in a week to 10 days and selectively remove suckers as they appear throughout the growing season.

Tips & Warnings

• Severe pruning increases the risk of blossom end rot in tomatoes.

References

• Cornell University: Diagnosing Tomato Problems
• Cornell University: Ten Mistakes to Avoid in Growing Tomatoes
• The University of Georgia College of Agricultural & Environmental Sciences: Blossom-end Rot

Resources

• University of Illinois Extension: Tomatoes
• Thehenrysplantfarm.com: Tomato Variety List