Left on their own, tomatoes will grow into shrubby, multi-stemmed plants that topple under the weight of their fruit. Fruit and foliage are more prone to attack by infestations and diseases when they're sprawled on the ground. Pruning your tomato plants and using plant supports can help create healthier, more productive tomato plants.1
Suckers are the shoots that form where side branches meet stems.Benefits of Pruning Tomato Plants
- Increases fruit production by redirecting a plant's energy from suckers to developing blossoms and fruits
- It keeps plants compact and gardens tidy
- Makes it easy to support plants using tomato ladders and other supports
- It increases air circulation between plants, therefore reducing the risk of disease2
How to Prune Tomato Plants
There are several ways to prune tomato plants, depending on the type of tomato and the support you use. As a rule, pruning is most helpful for indeterminate tomato varieties -- large plants that continue to grow taller and produce fruit until killed by frost. Determinate, or bush tomatoes, tend to be smaller and more manageable.3
Most tomato pruning involves removing suckers -- the shoots that form in the axils where side branches meet the stem. Remove suckers when they're small by pinching them off with your hand or snipping them with pruners.
If your goal is to maximize the harvest, prune suckers sparingly. A good compromise is to remove all suckers that grow below the first flower cluster. This helps keep the main supporting stem strong, but it doesn't remove upper suckers that will eventually produce flowers and fruit. Removing ALL the leaves and suckers will weaken the plant.
Prune sparingly, too, if you live in a place with intense summer sun, which can cause sunscald on fruits (fruit with tough, thickened skin and discolored areas).
With Tomato Cages, it's good practice to leave some of the suckers on the higher branches.Pruning and Supporting Tomato Plants
If space in your garden is at a premium, or if you're supporting plants with tomato ladders or stakes, it's best to prune your tomato plants to one or two main stems. To do this, pinch out all suckers. Otherwise, suckers will grow into additional stems and create a wide, bushy plant. The remaining main stems will grow strong and sturdy and will be easier to secure to the supports' uprights with plant ties.
Gardeners using Tomato Cages or Tomato Towers to support plants often pinch out the suckers on the lower stems but allow suckers higher up on the plant to grow.
