How to Prune Potted Tomato Plants

Tomatoes are a vine plant and have a tendency to produce many vines off a central stalk, which may lead to a large and sprawling plant. In containers, a sprawling plant not only takes up too much room, it may cause stress on the tomato. With limited soil nutrients and water available in a container, most of it must be used to fruit. Too many vines attempting to fruit drains these resources and stresses the plant. Pruning your potted tomatoes helps protect the yield so it can ripen fully on a healthy plant.

Things You'll Need

• Stake
• Plant ties
• Pruning shears
• Bleach

Instructions

1. Push a stake into the soil behind the tomato plant at the time of planting. Use a 4- to 5-foot stake, and push it in until it hits the bottom of the pot.

2. Tie the central vine of the plant to the stake as the plant grows. Secure plant ties or strips of cloth loosely, every 4 to 6 inches.

3. Prune in the afternoon after the dew has dried on the plant, and rinse your shears in a solution of 1 part bleach to 9 parts water to prevent the spread of disease between plants.

4. Prune off the suckers that form between the main stem and its branches. These begin as small nodules, similar to a leaf bud, at the joint between the main stem and side shoots. Pinch these off with your fingers as soon as they form, or snip them off with shears if they are already shooting.

5. Top the plant if you are growing an indeterminate variety of tomato to prevent it from outgrowing the pot. Cut off the top of the main vines when they reach the top of the stake to prevent them from growing taller. Determinate tomato types do not require topping.

Tips & Warnings

• Indeterminate tomatoes grow in height through the entire season while determinate only reach a certain height, usually 4 to 5 feet.

• Caged plants require less pruning, even in pots. Purchase or make a cage wide enough to set over the entire pot. Only top the plant if it is an indeterminate variety.

• Never prune away all the leaves. These are necessary to shade the fruit and prevent sunscald.

References

• University of Missouri Extension: Growing Garden Tomatoes