How to Prune Tomato Plants to Increase Fruit Production

Tomato plants are a favorite crop for home gardeners. There are three main types of tomato plants; determinate, semideterminate, and indeterminate. Less pruning is required for tomato plants that are being grown in wire cages, yet some shoots must be removed to let in sufficient light and air movement. Varieties of tomato plants that mature in less than 70 days will normally not require pruning.

Things You'll Need

• Clean garden knife

Instructions

1. Identify what type of tomato plant you have, as this will determine how the plant will be pruned. Indeterminate types grow from 5 to 8 feet tall. They have a fruit cluster on the stem which grows between every third leaf. Determinate tomatoes grow from 1½ to 5 feet tall, with the fruit cluster between each leaf. Semideterminate plants are in between, and usually grow 3 to 5 feet tall.

2. Plan to prune early in the morning. Use a clean gardening knife when pruning.

3. Break off suckers (these are what will become a stem), before they are 3 inches long for indeterminate tomatoes, or when suckers are between 2 to 4 inches long for determinate. Assuming the indeterminate is being trellised, leave three stems on each plant when they are spaced 3 feet apart, two stems on each plant if the spacing is 2 feet apart or one stem on a plant when spaced 12 inches apart.

4. Pinch off lateral suckers that grow in the axils of each leaf on a two-stemmed plant. Do this when they first appear. Remove all but the one directly below the first flowering cluster.

Tips & Warnings

• Always sanitize your gardening tools to avoid spreading disease.

• If you prune after the suckers are they grow to more than 4 inches long, this can adversely affect the size of the plant.

References

• Vegetables and Fruits; James Crockett; 1972
• University of Missouri Extension; Growing Home Garden Tomatoes
• NC State University; Pruning and Supporting Tomatoes

Resources

• Alabama Cooperative Extension; Horticulture Notes: Pruning Fresh-Market Tomatoes
• Watch your Garden Grow
• Easy Gardening with Tomatoes