How to Prune and Maintain Your Tomato Plants
Trim your way to a better tomato harvest.
Tomatoes are a pantry staple. They're a pivotal ingredient in everything from a classic BLT to tossed salad and enhance dishes like fresh-from-the grill hamburgers and your go-to lunchtime sandwich. While growing tomatoes in your backyard garden is a gratifying process, it's important to note that it's actually the removal process—or rather pruning—that's essential in helping the plant's overall health. You might not think about pruning when you think of these vegetable garden staples, but our experts say that a little maintenance can make a big difference in the productivity of your tomato plants.
How do you know if your tomato plant needs pruning?
While some tomato plants will greatly benefit from pruning, others will not. Before you start to trim, figure out which type of plant you have: determinate or indeterminate. "Determinate tomatoes grow to a particular size, flower, fruit, and finish well before the end of the season," explains Adrienne R. Roethling, the director of curation and mission delivery at Paul J. Ciener Botanical Garden. "Whereas indeterminate plants continue to grow and continue to flower and set fruit until fall." Indeterminate tomatoes can benefit from some pruning, according to Roethling, due to how quickly they grow. "It'll help keep the plants under control, from leaning and from over-fruiting." With determinate tomatoes, pruning tends to be more of a personal choice, depending on how many tomatoes you want your plant to produce during the growing season. If you're the only one eating them, for example, you may want to pinch off a few flowers to limit the number your plants produce.
How do you prune a tomato plant?
Before you prune, you will want to find your plant's main and secondary stems so that you can reduce the number of secondary stems, which are the ones that can cause leaning and over-fruiting. "The secondary shoots are just that, you have a main stem, or three to four [of] what you consider main stems, and secondary shoots that emerge from the crotch of a leaf stem," Roethling says. Removing some of the secondary stems and leaving the main stem intact should help solve most of the more common issues you see with indeterminate plants.
Just make sure you are using the right tool for the job. "Personally, I prefer pruning shears because I always have them handy in the garden (whereas my scissors stay in the house)," adds Justin Hancock, a Monrovia horticultural craftsman. And be sure to wipe your sheers down with alcohol if you're trimming more than one plant. "That way if there's a disease issue on one plant, you don't inadvertently spread it to another by pruning."
When should you prune a tomato plant?
The best time for pruning your tomato is when you are ready to plant it, according to Vicky Popat, CFO and tropical plant expert at PlantOGram, If you don't have pruning shears handy, she says pinching off the lower leaves of the plant will work as well. And make sure you're planting your tomato nice and deep. "This creates a stronger, healthier root system that will hold an abundance of tomatoes." You can continue to remove flowers from your tomato plants until they are about 12-18 inches tall to ensure an even hardier root system.
Towards the end of the season, you should remove any excess leaf growth and branches that do not have any fruit on them to allow the plant to focus its energy on the remaining parts. Pruning your tomato plant will improve the airflow for the plant, make harvesting fruit easier, and help your plant produce larger tomatoes in the long run.