Kalettes ‘Petit Posy’, also known by its botanical name Brassica oleracea (Hybrid Group), is a modern vegetable bred by crossing kale and Brussels sprouts. This unique vegetable originated in the United Kingdom in the early 2000s, developed by traditional breeding methods rather than genetic modification. The goal was to combine the best traits of both parent plants — the nutty sweetness of kale with the compact, rosette-like form of Brussels sprouts.

‘Petit Posy’ is part of a branded range called Kalettes, which was released to the public after over a decade of development. The name ‘Petit Posy’ refers to the plant’s charming appearance, as it produces small, open, frilly rosettes on tall stalks, resembling miniature ornamental bouquets. Its flavour is mild, slightly nutty and sweet, and it lacks the bitterness sometimes associated with Brussels sprouts.

Medicinally, Kalettes ‘Petit Posy’ shares the health benefits of both kale and Brussels sprouts. It is rich in vitamins C, K, and A, and contains powerful antioxidants, fibre, and glucosinolates — compounds that have been studied for their potential anti-cancer properties. These compounds support liver detoxification and may assist in reducing inflammation. Eating Kalettes can support heart health, boost the immune system, and contribute to overall cellular health thanks to its dense nutrient content.

How to grow Kalettes ‘Petit Posy’ from seed:

Start seeds in late summer to early autumn, depending on your local climate.

Sow seeds in seed trays or directly into a well-prepared garden bed in full sun with rich, well-drained soil. The seeds germinate best at temperatures between 10°C and 25°C.

Once seedlings are large enough to handle, transplant them with good spacing — around 60 to 70 cm apart — as the plants can become quite large.

They require regular watering, especially during dry periods, and benefit from a regular feed of seaweed solution or balanced fertiliser.

The plants take several months to mature, with harvest typically occurring from mid-winter into spring.

These grow on a tall central stem like Brussels Sprouts do, except the kalettes take the place of the sprouts! As the lower leaves yellow and drop, the small leafy rosettes form in the leaf axils and can be picked individually as they reach around 3 to 5 cm in size. Regular harvesting encourages further growth up the stem.

Kalettes ‘Petit Posy’ is a rewarding and ornamental vegetable that not only looks lovely in the garden but also offers exceptional nutritional value for the plate!

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Euronaut, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons

Debhatter, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons

Kgbo, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons