Knowing how to prune tomato plants is worthwhile when growing these tasty fruits. However, the right approach depends on the type of tomato you’re growing.
The two main groups of tomatoes are cordon (sometimes called indeterminate) and bush (or determinate). The former grow tall, while the latter are better for compact spaces and container garden trends.
Cordon tomatoes are the ones that benefit the most from a trim, as it keeps their size under control and encourages better yields. Bush tomatoes, on the other hand, can be more or less left to their own devices.
For advice on this summer garden job, I turned to the gardening experts. Below, they reveal their top tips, including recommended timings and tools.
How to prune tomato plants, according to gardening pros
Follow these easy gardening tips on how to prune tomato plants for the best results from your summer crop.
How to prune cordon tomatoes
Cordon tomatoes are usually grown on a tall, single stem. Examples of this type include “Shirley”, available from Crocus, and “Ildi”, from Thompson & Morgan – a yellow, cherry variety.
Nelly Hall, the brand director at Alitex, says cordon tomatoes are continuous growers that can reach impressive heights if not managed properly. “Regular pruning is essential here,” she says.
She explains how removing the suckers prevents the plant from becoming too bushy and directs its energy towards producing fruit. “This also helps improve air circulation and helps reduce the risk of disease," she adds.
The technique for this is simple: according to Pim Dickson of Mr Fothergill's Seeds Limited, all you need to do is remove the little shoots that appear in the crook above where a leaf joins the main central stem.
“When an indeterminate tomato is tall enough and fills the space you want, you can then pinch out the growing tip, so it grows no taller,” Pim continues. “Usually this is when six to seven trusses of fruit have started to set.”
Lower leaves that have turned yellow can also be removed as the crop matures, Pim adds. “This will help fruit ripen and reduce the chance of disease from dying leaves.”
There are other benefits to pruning these tomatoes, too. Petar Ivanov, a gardening expert at Fantastic Services, highlights how it makes it easier to see and pick the tomatoes and reduces hiding places for pests.
Top tip: As well as pruning, these plants need support. If you're using soft twine, consider Sarah Raven's advice on tying in climbing plants. We also like the look of this adjustable tomato crop booster frame from Crocus.
How to prune bush tomatoes
Nelly explains that bush tomatoes grow to a certain size, set fruit, and then stop growing. This makes them easier to care for, and perfect for small gardens.
“Because they have a set growth pattern, they require little to no pruning," she says. Her advice is to simply trim away the bottom leaves to prevent them from touching the ground beneath.
Examples of bush tomatoes include “Red Alert” from Crocus, a sweet-tasting cherry variety. Meanwhile, a favourite variety of Nelly’s is “Veranda Red” (available from Thompson & Morgan). They are a beautiful addition to summer salads, she says, and can be grown on greenhouse benching due to their relatively compact size.
Top tip: Pim notes how larger types of bush tomatoes only need support if the trusses of fruit get too heavy.
FAQs
What tools should you use to prune tomatoes?
Now you know the techniques for how to prune tomato plants, you may be wondering which tools to use.
Petar recommends using sharp, clean pruning shears to make clean cuts without damaging the plant. These essential garden tools will also come in handy when deadheading other plants in your plot. “Garden scissors will help you with smaller and more delicate cuts,” he adds.
You can also pinch out smaller side shoots with your fingers, notes Nelly.
“Make sure to wear gloves to protect your hands from the plant’s sap, which can cause skin irritation,” Petar notes. These gardening gloves from Sarah Raven are machine washable, with different sizes available.
When should you prune tomatoes?
Nelly recommends pruning indeterminate tomato plants every couple of weeks for bigger, juicier fruits. She also advises carrying out the task first thing in the morning, after watering the plants.
Petar adds: “If the plant looks stressed or unhealthy, reduce the amount of pruning to avoid further stress.”
Looking for more tips on growing your own delicious crops? Our guide on vegetable gardening for beginners has plenty of practical advice.
