Pruning tomato plants means removing small side shoots so the plant puts its energy into fruit instead of extra leaves. This technique is often called sideshooting.1
Not every tomato needs it. Whether you should prune depends entirely on which type you are growing.
Which tomatoes need pruning
Cordon tomatoes, also known as indeterminate tomatoes, grow as tall single-stemmed plants and need regular pruning to maximise fruiting and keep airflow good between plants.1
These vigorous plants are trained upright on a support, with the main stem tied in as it grows.1
Without this training and pruning, they sprawl into a tangled mass of stems along the ground, which produces fewer fruit and is more prone to disease.1
Trailing or bush tomatoes, known as determinate tomatoes, do not need this regular pruning.1
Knowing whether you have a determinate or indeterminate variety is the first step before you make any cuts, since suckers are located and removed accordingly.6
Why pruning helps your harvest
Pruning directs a tomato plant's energy toward producing fruit rather than extra foliage.1,,5
Done well, it speeds up ripening, helps control the overall size of the plant, and can even influence the size of the ripe fruit.5
For gardeners with young children or pets in the garden, a well-pruned, upright cordon tomato on a stake or cane is also easier to keep tidy and out of curious reach than a sprawling, tangled plant.
What to actually remove
The main targets are sideshoots, sometimes called suckers, that appear in the leaf joints of cordon tomatoes.1,,6
Removing them regularly is the core of the sideshooting technique, done alongside training the main stem onto a support so the plant grows upright rather than sprawling.1
Snip or pinch these shoots out while they are still small, since letting them grow on turns a single-stemmed cordon into a multi-stemmed, congested plant.1
Timing it right through the season
Pruning is an ongoing job through the growing season for cordon types, not a one-off spring task, since new sideshoots keep appearing at leaf joints as the plant grows.1
Check plants regularly, roughly every week or so during peak summer growth, and remove new shoots while they are small and easy to pinch out by hand.
Working through your tomato patch on a warm, dry morning makes the small wounds left behind heal faster, which lowers the risk of disease getting in.
Keeping plants healthy while you prune
Good airflow between plants is one of the main reasons cordon tomatoes are pruned in the first place, since congested growth is more liable to diseases and other problems.1
If you use pruning shears or a knife rather than pinching by hand, wipe the blade clean between plants to avoid spreading any disease from one tomato to the next.
Any spray you might use afterward to manage pests or disease should always be applied strictly according to the product label, and kept safely away from children, pets, and garden ponds or water features.
A simple habit for a better crop
The core idea from every angle is the same: pruning tomato plants, especially indeterminate cordon varieties, channels the plant's energy into fruit rather than sprawling foliage.1,,4,,5
Learn to tell your determinate bush tomatoes from your indeterminate cordon types, then make sideshoot removal a regular part of your summer garden routine.6
A little snipping each week, paired with steady support and training up a cane or stake, is often the difference between a tangled patch and a productive one.1