Biting into a sweet, succulent cherry tomato is one of the joys of summer, and somehow it tastes even better when you grew it yourself. Cherry tomatoes are not difficult to grow in a home garden, but just because cherry tomatoes are petite doesn't mean the plants are; like many tomato cultivars, some cherry tomato plants have a tendency to sprawl, and there are many good reasons to tidy them up. With some basic pruning techniques, you can trim back your cherry tomato plants fairly quickly, and get back to enjoying your summer salad.
Types to Prune
Tomato plants fall into one of two types: determinate and indeterminate. They are determinate if they form a terminal, or top, flower cluster, which is what causes them to stop growing in height. Because they grow to a fixed size and produce a fixed number of cherry tomatoes, determinates should not be pruned, although you should remove the shoots below the first flower cluster. Plants with lateral flower clusters, and no terminal, are indeterminates; their fruit ripens more slowly, and they will keep growing until killed by frost. These are the type of cherry tomato plants which should be pruned. Indeterminate cherry tomato cultivars include Super Sweets, Sweet Million, Large Red Cherry and Yellow Pear; determinate varieties include Tiny Tim and Mountain Belle.
Benefits of Pruning
Prune your indeterminates to maximize the efficiency of photosynthesis and minimize disease. In the process of vigorous growing, they send out "suckers", or shoots, that come from the main stem and can turn into main stems themselves, which send out more shoots. Although this makes the plant produce more fruit, the benefit is outweighed when the main stem can no longer bear the weight and the plant sprawls on the ground. This is not only unsightly but destructive; as fruit falls in the dirt, it is exposed to damage from insects and viruses. On the other hand, a pruned and supported single-stem tomato plant has all its fruit in the air, its leaves exposed to the sun, and flavor-enhancing sugar going to the developing fruit, since the plant is only growing at the tip. The cherry tomatoes will be larger and tastier, and will form more quickly. In addition, the leaves dry off faster when it the plant is pruned and supported, reducing the risk of bacterial and fungal infections.
Prune the cherry tomato plant to one or—at most—two main stems, and remove lower branches to deter splashback reinfection of pathogens left in the dirt from previous years. Pinch the new suckers soon after they appear. The best way to do this is with your fingers, twisting the sucker until it snaps off; this results in a more desirable break from the stem than would occur with the use of scissors. If you've let suckers grow too long and they are hard to snap off manually, use a retractable knife. Avoid sun scald by leaving enough leaves to cover and protect the tomatoes, and prevent fungal infection by never pruning a wet tomato plant. Keep cherry tomatoes free of side stems below the first fruit cluster.