The way to Prune a Tomato Vine
While tomatoes may sprawl inside cages, you are going to get stronger plants and bigger fruit once you prune the plants to guide their growth. Learning some tomato plant terminology before you go out to the garden helps you prune properly and prune just the plants that benefit from the attention. Indeterminate tomatoes, for instance, are those that grow all season with no predetermined height — some reaching over 10 feet tall — while determinate plants generally stop growing at 3 to 4 feet. On the plant itself, it helps to know that the leaf axil is the joint between the leaf and principal stem, and a sucker is actually the shoot that forms there.
Pinch off suckers from ground level to the second set of suckers below the initial truss of flowers or developing fruit on indeterminate and determinate tomato plants. Pinch small ones between your index finger and thumb or snap off bigger ones early in the day once the plant is filled with moisture. Suckers develop fruit and flowers, but those in the bottom are too shaded to produce high-quality fruit and lead to a plant with crowded growth that’s more vulnerable to disease from poor air flow and also from moisture splashing on leaves close to the ground when you water the plants.
Tie indeterminate vines into your trellis or stake with brief lengths of twine as they grow, allowing up to 3 principal stalks to develop from the last one or two suckers prior to the first set of flowers. Train these suckers into additional main stems, tying them up to separate bets as they grow.
Inspect the plant on a weekly basis from the base of the vine up, cut-off suckers from all the main stems to avoid more stems from developing. The more stems a plant has, the more of its own energy and also the sugar that the plant produces goes to foliage production, rather than fruit production.
Pinch off the growing tip of each main stem once the vine reaches the surface of the stake or in late summer to stop additional fruit from creating that won’t have time to reach maturity.
Analyze both determinate and indeterminate plants as they grow for signs of disease and pest infestation. Leaves influenced by fungal disease display black or dark brown circular spots and yellowing. Leaves and comes with sticky honeydew residue that turns to soft black sooty mould, yellowing and twisted leaves and stunted stems are infested with aphids. People with signs of honeydew and leaves that appear dried and yellow or silver in patches are infested with whiteflies.
Eliminate all infested or diseased foliage and stems on either type of plant with hand pruners. Sterilize pruning tools between plants with full-strength household antiseptic cleaner to prevent spreading disease or infestation from plant to plant.
Clear all pruned and fallen leaf from across the plants to avoid the spread of disease and eliminate a location where insects may overwinter to infest next year’s plants.