Kale is one of the oldest cultivated leaf‑cabbage types in Europe and West Asia. Early forms emerged from wild Brassica species and were already used and refined by ancient cultures. Over regional cultivation and trade routes, numerous types developed over time, differing in leaf structure, colour and flavour. The diversity ranges from finely curled, tender leaves to robust, broad‑leaved varieties, including colour variations in deep green, blue‑green and slightly violet tones.

In subtropical climates, kale thrives particularly well during the milder seasons, as it prefers balanced conditions and consistent moisture. Even under warmer conditions, the right variety can be grown reliably with sufficient watering. In temperate regions, many traditional and historically preserved open‑pollinated varieties excel thanks to their pronounced winter hardiness, producing aromatic, vigorous leaves even in frost. Kale shows excellent ecological adaptability and can be cultivated reliably in many climate zones when timed correctly.