What Happens When You Cut The Tops Off Tomato Plants?

Growing your own tomatoes is one of the most rewarding summertime activities, but when it comes to pruning practices, it's not always the most intuitive. There's one particular move, called "topping," that is exactly what it sounds like: cutting off the tippy-top of the tomato plant. This gardening technique can technically improve fruit production and help tomatoes ripen before the growing season ends, but it largely depends on your tomato variety and the timing of seasons. 

Tomatoes are divided into two types, indeterminate and determinate, and knowing the difference is key to any tomato gardening hacks you want to try out. Determinate varieties, often called bush tomatoes, are genetically programmed to stop growing after they reach a certain size. Because they stay "bushy" and on the shorter side, topping isn't necessary here. Removing the growing tip would only destroy any future flower clusters that would have eventually produced tomatoes. 

Indeterminates are a different story. They continue growing, flowering, and producing fruit until the first frost kills them off. Topping these redirects the plant's energy. Once that growing tip is cut off, the plant stops investing its precious resources in new stems, leaves, and flowers. Instead, it channels that energy into growing and ripening the tomatoes that are already hanging out on the vine. This isn't necessarily something you should practice on the regular, but it can be helpful in regions with a short growing period, or when the first frost is just a few weeks away.

To top an indeterminate plant, you'll want to look for the main stem and grab a clean, sharp pair of gardening shears. Cut the stem just above the last healthy leaf node or fruit cluster. Some gardeners even remove any flowers that reappear after the cut, since those yellow blossoms are unlikely to produce edible tomatoes by the time the first frost rolls around. 

Another side bonus to topping is that it can help you tame an extra-tall tomato plant. Some of the indeterminate varieties can go as high as 12 feet, which means it's likely they've outgrown their support structure. Harvesting any tomatoes up there will require a ladder and some gymnastic moves. Topping also helps the little guys growing at the bottom of the plant, as it provides extra sunlight to poke through and overall better air circulation. Just be sure you don't top too early in the season. Tomato plants require continuous growth to produce flowers and fruit throughout the summer, and topping too early prematurely stops the plant from producing any new fruiting stems.

Understanding your variety and pruning tomato plants at the right times can help maximize your tomato quality, but it's totally up to you. Topping is more of a strategic technique for gardeners than just regular, routine maintenance. There are many mistakes to avoid when growing tomatoes, but luckily, choosing to forego topping isn't a big one.