25 October 2019

Tasty tomatoes

We take a look at a salad hero that's one of the world's favourite fruits.

By Hélèna Dove

Tomatoes, Kitchen Garden, Meg Boldison © RBG Kew

From sauces to salads, the tomato (Solanum lycopersicum) is a prized ingredient in many of our favourite dishes. 

A member of the nightshade family along with aubergines and peppers, tomatoes come in many different shapes, sizes and colours. This year in the Kitchen Garden we've experimented with some new varieties. 

‘San Marzano’ tomatoes, Kitchen Garden
‘San Marzano’ tomatoes, Kitchen Garden, Meg Boldison © RBG Kew

Wild beginnings 

Despite being considered an Italian essential, tomatoes actually originated from the Andes. They grew wild, and looked very different from the modern tomato. Before cultivation they were small, fragrant fruits, similar to the size of a cherry tomato. 

Commercial tomato cultivation began in the mid-nineteenth century, and they're now one of the most widely grown fruits in the world. 

Colours of the rainbow 

Tomatoes come in many different shapes, sizes and colours. Generally tomatoes are red with yellow flesh, but they can also be purple, orange and yellow with a variety of flesh colours.

They're an urban gardeners dream, as small, tumbling varieties can be grown in a hanging basket or a pot on a balcony. 

Tomato 'Shirley' in the Kitchen Garden
Tomato 'Shirley' Kitchen Garden, Zoe Stewart © RBG Kew
Tomato 'Shirley' Kitchen Garden
Tomato 'Shirley' Kitchen Garden, Zoe Stewart © RBG Kew

Sensitive souls 

Tomatoes aren't hardy, so need to be sown in April with some artificial heat and protection.

At Kew we grow them in glasshouses on a cosy heat mat. Once they have their leaves, we plant the seedlings out into pots. We make sure to plant the tomatoes outdoors once all chance of frost has passed to prevent them dying, and we use supports to help them grow tall. 

Towards the end of summer, we pinch out the growing points and thin the fruit. Pinching plants is a form of pruning that encourages branching on the plant. 

This technique allows the plant to put its energy into ripening existing tomatoes before the first frosts.

'Outdoor girl' tomato, Kitchen Garden
'Outdoor girl' tomato, Kitchen Garden, © Helena Dove

Mix it up 

We've experimented with some new cultivars this year.

We've grown cultivars that ripen in cooler temperatures, such as ‘Outdoor Girl’ which has vivid red fruits and ‘Black Russian' originally from Russia which produces a dark red-black, beefsteak tomato. 

We've had success with some great heritage varieties, such as 'Shirley’ which is a bright red tomato that tends to ripen earlier than other varieties, and 'Tigerella', a variety with pretty orange stripes. 

Try growing tomatoes on your own windowsill with the help of a growbar. 

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