Why Are My Tomatoes Splitting?

Few things are more disappointing than spotting a perfectly ripe tomato only to find it's cracked open. The good news? Split tomatoes are a common problem, especially during the UK summer, and they're usually easy to prevent.

Here's why tomatoes split, what you can do to stop it happening, and whether they're still safe to eat.

Why do tomatoes split?

The most common cause is inconsistent watering.

When tomato plants go through a dry spell and then suddenly receive lots of water from heavy rain or generous watering, the fruit absorbs moisture very quickly. The inside expands faster than the skin can stretch, causing the tomato to crack.

This is particularly common during July and August when warm weather is followed by summer showers.

Different types of splitting

There are two main types of cracks you'll see:

Radial cracks – these run from the top of the tomato down the sides and are usually caused by sudden changes in soil moisture.

Concentric cracks – circular cracks that form around the stem. These are often linked to rapid growth or temperature fluctuations.

Both are common and don't necessarily mean your plant is unhealthy.

How to prevent tomatoes from splitting

A few simple changes can make a big difference.

Water consistently – aim to keep the soil evenly moist rather than allowing it to dry out completely.

Mulch around your plants – adding compost, bark or straw helps lock moisture into the soil and reduces sudden fluctuations.

Harvest little and often – don't leave fully ripe tomatoes on the vine for too long, especially if rain is forecast.

Grow in pots with care – containers dry out much faster than garden beds, so check them daily during hot weather.

Feed regularly – healthy plants are better able to cope with changing weather conditions.

Can you still eat split tomatoes?

Yes! As long as the crack is fresh and the tomato hasn't gone mouldy or started to rot, it's perfectly safe to eat.

Simply cut away any damaged part and enjoy the rest. However, if the fruit has been split for several days or has become soft and mouldy, it's best to compost it.

Top tips for healthier tomato plants

Water at the base of the plant rather than over the leaves.

Water early in the morning or later in the evening.

Remove yellowing lower leaves to improve airflow.

Feed weekly with a tomato fertiliser once fruits begin to form.

Support plants with canes or cages as they grow.

Visit Flowerland for everything your tomatoes need

Whether you're growing tomatoes in the greenhouse, garden, or on your patio, we have everything you need to help them thrive. From specialist tomato feed and compost to pots, supports, watering cans and mulch, you'll find plenty of inspiration at both our Bourne End and Iver centres.

Our team is always happy to offer advice, so if your tomatoes aren't looking their best, pop in and chat with one of our gardening experts.