Big Rainbow tomato: plant care, taste & more

Regina
Regina
Regina
Regina

I studied horticultural sciences at university and in my free time you can find me in my own patch of land, growing anything with roots. I am particularly passionate about self-sufficiency and seasonal food.

Favourite fruit: quince, cornelian cherry and blueberries
Favourite vegetables: peas, tomatoes and garlic

The ‘Big Rainbow’ tomato’s name says it all: this beefsteak tomato has an unusual look with up to three different colours. Find out how to best grow and care for ‘Big Rainbow’ tomatoes in this article.

cut big rainbow tomato
The ‘Big Rainbow’ tomato’s flesh is also tri-coloured [Photo: Julie Vader/ Shutterstock.com]

The ‘Big Rainbow’ tomato variety is a large tomato that has warm shades of red, yellow and orange all at once when ripe. Read on to discover this unique heirloom variety and our top tips on how to plant and care for the ‘Big Rainbow’ tomato plant.

‘Big Rainbow’ tomato: profile

FruitBeefsteak tomato; yellow with red and orange stripes
FlavourFruity, balanced sweet and acidic taste
Ripening timeMid–late
GrowthIndeterminate, up to 180cm in height
LocationGreenhouse, outdoors, and in containers

‘Big Rainbow’ tomato: origin and history

The ‘Big Rainbow’ is an heirloom tomato variety that was given to the Minnesota Seed Savers Exchange’s collection by Dorothy Beiswenger in 1983. A few years later, around 1990, the beefsteak tomato finally came onto the market and has been cultivated and propagated ever since. The tomato’s colour and size is reminiscent of the ‘Hillbilly’ tomato variety.

Taste and other characteristics

‘Big Rainbow’ tomato plants grow up to 180 centimetres in height and are quite fuzzy. They produce large, slightly ribbed and platelike fruits. Measuring up to 500 grams in weight and 10 centimetres wide, ‘Big Rainbow’ tomatoes definitively belong to the beefsteak tomato group. The fruits begin to ripen in mid-late August and as an indeterminate tomato variety, it will bear fruit reliably and abundantly until the end of October.

Once the tomatoes begin to ripen in summer, their yellow, red and orange stripes and marbling provide a beautiful sight. The tomatoes are sweet and fruity with a balanced acidity, so even people with sensitive stomachs can enjoy them! Being an heirloom variety, you can save the ‘Big Rainbow’ tomato seeds to grow the plants again next year.

big rainbow tomatoes
The large beefsteak tomato ‘Big Rainbow’ is a beautiful sight with its unique stripes and marbling [Photo: Chertamchu/ Shutterstock.com]

How to grow ‘Big Rainbow’ tomatoes

The ‘Big Rainbow’ tomato grows well both in a greenhouse or outdoors in a bed or containers.

Plant young ‘Big rainbow’ tomato plants indoors in a greenhouse or polytunnel around the beginning of May or outdoors from mid-May onwards, once the threat of frost has completely passed. Make sure to harden off your tomato plants before moving them outdoors in cooler climates. To harden off young tomato plants, put them outdoors for an increasingly long period of time over the course of ten days.

A sheltered spot in the garden is perfect for ‘Big rainbow’ tomato plants, as their fruits are sensitive to rain and will burst if too wet. If planting in a container, choose as large a pot as possible to meet this indeterminate tomato’s needs. We recommend planting ‘Big Rainbow’ tomato plants in slightly acidic soil that is packed with essential nutrients for these hungry plants, such as our Plantura Organic Tomato & Vegetable Compost. Once planted, water your ‘Big Rainbow’ tomato plants generously and support them with a stick.

Plantura Organic Vegetable Compost
Plantura Organic Vegetable Compost

Peat-free & environmentally-friendly: for tomatoes & all other vegetables, ensures a rich & aromatic harvest, child & pet friendly

Beefsteak tomatoes should only be grown with one or two shoots; it is necessary to prick out tomatoes so that there are fewer, stronger shoots develop that can bear the heavy weight of the fruit. Remove all the other side shoots regularly. You can ferment the pricked out shoots to make a fortifying liquid tomato food. To make a fertiliser from the shoots, simply use the same method as making nettle tea fertiliser, however, apply with a dilution ratio of 1:20 when watering.

Fertilising nightshade plants, such as the ‘Big Rainbow’ tomato plant, should be done from June onwards as the plant’s first fruits begin to grow. Liquid fertiliser, such as our Plantura Liquid Tomato Food, can be applied when watering, so it flushes nutrients directly to the plant’s roots.

Plantura Liquid Tomato Food
Plantura Liquid Tomato Food

Liquid fertiliser with an NK ratio of 4-5, for tomatoes & other vegetables, promotes healthy plant growth, child & pet friendly

Harvesting and using ‘Big Rainbow’ tomatoes

 The juicy ‘Big Rainbow’ tomato is excellent in salads but can also be enjoyed sliced on bread and burgers. ‘Big Rainbow’ tomatoes can also be cooked and bring a mild, sweet and fruity flavour to sauces or soups.

Heirloom tomato varieties only need to be bought once, because with little effort you can obtain, dry and store the tomato seeds yourself. Read our article on saving tomato seeds to find out more.

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