By now, all of the baby tomato transplants that we put in the ground earlier this spring are starting to grow and produce fruit! Be sure that you have healthy tomato plants by pruning them occasionally throughout their production season.
Tomato Pruning: Bigger Fruits, Healthier Plants
Ellen Orabone
Why Prune Tomatoes?
- To grow more flavorful tomatoes.
- To grow larger tomatoes.
- To grow more tomatoes over the length of a season.
- To keep plant leaves and fruits off the ground and away from pests, insect damage, and fungal disease.
- To keep plants smaller and more compact.
- To allow tomatoes on the plant at the end of the season to ripen before the first frost.
When we prune our tomato plants, we are diverting the energy the plant uses to grow foliage to the part of the plant that produces fruit. If there are more branches on the plant that are not producing fruit, there is more energy being directed to that part of the plant instead of to the fruiting part. By pruning away excess foliage, you can produce larger fruit earlier in the season and protect your plants from pests and diseases.
Pruning Principles
- Prune to create one to four strong stems.
- Prune each stem to about the same length. Prune to keep the plant at a manageable size.
- Prune to keep leaves and stems off the ground by removing the leaves and stems below the first set of fruit.
- Prune so that leave do not shade other leaves.
- Avoid pruning away leaves above fruit clusters; these leaves protect fruit and stems below from sunburn.
- Prune to allow air circulation to the center of the plant. Air circulation helps deter diseases and insects.
Pruning Basics
To prune your tomato plant, look for the suckers that grow in the “V” space between the main stem and branches. While these suckers can eventually become full-grown branches and produce fruit, the tomato plant can become too large with the additional foliage and will not produce as much fruit in the long-run. You can pluck these suckers off with your fingers if they are less than 2 inches long, or you can prune them off with shearers if they are larger.
We also recommend pruning the bottom branches of tomato plants as well. That way, when fruits are produced on lower branches, they do not touch the soil below and act as a bridge for pests to continue up the plant. Also, keeping the base of the plant cleaner will allow for a healthier plant overall and for larger fruits. Be sure that when you are pruning your plant, you are using clean pruning shears so as not to transfer any diseases from previous cuts, and that you do not remove too much foliage at once so as not to stress out the plant.
Follow these steps for properly pruned tomatoes:
- After the plant is 12 to 18 inches tall, allow the first set of blossoms to grow. (Nip away any blossoms that come before.) This first set of blossoms will become the plant’s first fruit cluster.
- Remove all of the leaves and suckers below the first blossom cluster. They are not needed.
- When you decide to prune, do not pinch away the growth tip too soon. Allow two sets of leaves to develop on a sucker or side shoot before pinching out the growth tip. Pinch above the two sets of leaves; these leaves will protect fruit and stems below from sun damage.
- Re-check the plant once a week to pinch out new unwanted growing tips.
- When the plant reaches the desired height–usually no taller than its support, 4 or 5 feet is good–consistently pinch out all new growing tips. In a week or so time, the plant will quit trying to put out new growth at the topmost part of the plant and concentrate on new growth and fruit below. Continue to pinch out any new growth that you do not want. Keep training this way and the plant will develop a more compact shape, and it will begin to flower and set fruit more heavily throughout its height.
To practice your tomato pruning and a variety other gardening skills, sign up for one of our classes held throughout the year. Explore our class offerings here.