Home & Garden Garden Should You Prune Your Tomato Plants? By Ramon Gonzalez Ramon Gonzalez Writer Columbia College Chicago Roman Gonzalez is the creator of the urban gardening blog MrBrownThumb, founder of the Chicago Seed Library, and a co-founder of One Seed Chicago. Learn about our editorial process Updated October 11, 2018 MrBrownThumb Share Twitter Pinterest Email Home & Garden Planting Guides Indoor Gardening Urban Farms Insects Ask 10 gardeners if you should prune tomato plants and you may come away with 10 different answers. Some gardeners swear by pruning, while others don’t see the benefit of pruning their plants at all. Watch Pruning Tomatoes for Production One aspect of tomato pruning that I do follow and recommend is removing suckers from the crotch (where the stem and a branch meet) whenever I spot them. If left to grow, the sucker will develop into a branch of its own, flower and even set fruit. Why You Should Prune Tomato Suckers The thinking behind pruning suckers is that they compete with the plant for vital nutrients, water, space and light. Allowing suckers to mature into a branch can result in a plant that produces a smaller overall crop. Some tomato growers swear by only letting a select number of branches produce fruit, but I find that removing the suckers is enough to ensure a decent batch of tomatoes. Why You Shouldn’t Prune Tomato Suckers If you’re growing determinate tomatoes in your garden pruning is counterproductive. Determinate tomatoes are only going to grow to a certain height and produce fruits. By removing suckers you’re lessening the amount of tomatoes you’ll harvest. On the other hand, some pruning of indeterminate tomatoes may be a good thing to keep the plant from getting too heavy and growing out of control. How to Prune Tomato Suckers The best time to prune suckers off of your plant is when they are young like in the picture above. At this stage of growth you can simply snap off the sucker with your thumb and index finger. If the sucker is as thick as a pencil a sharp knife or hand-held pruners should be used. Sterilize the knife or shears after ever cut to lessen the chances of spreading a disease that will kill your tomato plant. If you didn’t notice the sucker until it grew to a size thicker than a pencil, I would recommend just leaving it alone and allowing it to flower and fruit. I’ve damaged and killed many a tomato plant by trying to remove a sucker that was just too thick. It is better to be safe than sorry.