How to Plant, Stake, and Prune Tomatoes, Part II (Staking and Pruning)
Now that the plants are in the garden, it is time to focus on supporting their development. All tomato plants need to be supported and pruned. Tomato plants that aren't given adequate support or pruning will topple over quickly and become a jungle of branches. Most importantly, though, without this care, they will not produce healthy, prolific fruit.
How to Stake Tomato Plants
Do not wait until the plants are tall to set-up stakes. Stake tomato plants while they are still young. This reduces the need to bend or move branches to fit into a tomato cage, which can damage the plant. Staking is necessary for all tomato plants, so they don't fall over with the weight of the fruit, and to keep the fruit off the ground where it will rot quickly. Plants loaded with fruit are quite heavy, so be sure to anchor the supports in the ground securely.
These round, wire structures, are placed around the young plant to support the limbs. Cages work well with small, determinate tomato varieties. They are not strong enough for indeterminate types, though.
Wooden stakes come in a variety of sizes and work for determinate and indeterminate tomato types. Always use stakes that are taller than the anticipated height of the plant. Determinate varieties may only need one 4' stake. Indeterminate types usually need 2 8' stakes placed on either side of the plant. Use plant twine or wire to join the stakes together, and then use twine to hook the branches to the horizontal wire.
A trellis is especially recommended for indeterminate tomato varieties. Pound wood or metal stakes into the ground 6-8' apart. Then, run baling wire horizontally across the stakes every 12 inches. Use gardening twine or plant tape to hook the tomato branches to the horizontal wire.
Always tie the tomato branches to the support wire or stake loosely to prevent damage.
How to Prune Tomato Plants
Untended tomato plants become a tangle of branches with scarce fruit. Most often, the plant will focus its' energy on growing more branches instead of growing fruit. This is, of course, not what you want! Indeterminate varieties, in particular, will become wild and jungle-like if they are not pruned regularly.
Tomatoes love branching out and will try to grow multiple stems near the base of the plant. For smaller determinate varieties, it is best to keep the tomato plant to one stem. Remove any stems starting near the bottom and continue to do so for the life of the plant. Tomatoes will continuously try to grow more stems, so you have to keep a persistent eye on them to prevent it.
The removal of any stems attempting to grow near the base is also essential for disease-prevention. Soil-borne diseases are less likely to reach the leaves of a plant that has a 10” area cleared at the base of the stem.
For indeterminate tomatoes, if there is enough support, they can be allowed to grow several stems. However, you must still keep an eye on them because they will try to grow much more. Decide which ones to keep and remove all others.
These side-stems, called suckers, don't just occur at the base of the plant. They start in the crook of the stem and the branch, and they will grow in every junction possible. Remove them as they appear, especially higher up on the plant. Suckers take energy away from fruit production, and if allowed to grow unabated will make the plant top-heavy and more likely to topple over.
Do not prune the suckers off determinate tomato varieties; only do it with the indeterminate types. Determinate tomatoes grow to a certain height and set fruit all at one time. Pruning does not affect plant growth, and the removal of suckers may negatively affect fruit production.
At the end of the season, about a month before the first frost, encourage the tomato plant to ripen any remaining fruit by pruning off the tops of each stem right above the fruit cluster.
Now is the time to start those tomato plants, if you haven't already. Follow these simple measures, and soon you'll be plucking loads of delicious, juicy tomatoes from your garden.