July is a pivotal month for anyone growing tomatoes outdoors in the UK. By now, your plants should be well-established and likely starting to set their first trusses of fruit. The weather can be unpredictable, but the warm summer days are exactly what these plants crave to turn those small green marbles into juicy, sun-ripened crops. 

The most important thing you can do right now is stay consistent with your watering routine. Because outdoor plants are exposed to wind and fluctuating temperatures, they can dry out surprisingly quickly, especially those in pots or grow bags. Aim to keep the soil consistently moist but never waterlogged; irregular watering is the main culprit behind split skins and blossom-end rot. Always direct your water at the base of the plant, avoiding the leaves to reduce the risk of fungal issues like blight, which thrives in humid conditions.

Feeding is another essential task for this time of year. As the plants shift their energy from growing foliage to producing fruit, they become quite “hungry.” Using a dedicated liquid tomato feed once a week, which is typically rich in potash, will give them the boost they need to produce a bountiful harvest. If you are growing cordon or “vine” varieties, keep a close eye on the side-shoots—those small, leafy stems sprouting in the “armpits” between the main stem and the branches. Pinch these out regularly, as they sap energy that the plant should be putting into its fruit.

Finally, keep an eye on your supports. As the fruit gets heavier, your plants can easily become top-heavy and topple over in a strong breeze. Ensure your canes are sturdy and the stems are tied in securely with soft twine. A little bit of daily attention now will ensure you’re rewarded with the best flavour come harvest time.