Edible kale (Brassica oleracea Acephala Group, ht 20-40 cm) belongs to the mustard family (Brassicaceae) and has become a popular food in recent years, attributed with many health benefits. It is rich in vitamins A, C and K, as well as in potassium and calcium, and is low in carbohydrates. Kale is used in salads, stir-fries and many vegetable dishes. Traditionally regarded as a winter crop, I have found that certain varieties will grow year-round in my Sydney garden. In the cooler months it is best grown in a sunny spot, but if growing in the warmer seasons, it is better to grow it in part-shade to prevent it from bolting to seed.
There are many decorative forms of edible kale, with curled or crinkly and/or coloured leaves of various shapes and sizes, which can look most attractive. I have had most success with a non-hybrid dwarf green kale, which grows for at least 12 months before becoming too woody. Kale can grow in a pot or in the ground. Sow from seed, preferably where you want it to grow, though the seedlings can be transplanted with care. Give kale organic-rich soil with some lime added. Water regularly and apply a liquid fertiliser once a week. The leaves can be harvested a few at a time from each plant; they will regrow. Kale, like many edibles from the Brassicaceae family, is prone to attack by the white cabbage moth. For that reason, I grow mine in a trough under a wooden frame covered in fine mesh to exclude this pest. Kale can be grown as a microgreen crop.
So-called ornamental kale' is also classified under this name. They are used for bedding or pots and have lobed or dissected veined leaves in hues of purple, pink, yellow or white. They have become popular in floral arrangements as they are long-lasting in a vase. Osaka Series is a popular strain with frilly-edged leaves and mixed colours. Grow in the same conditions as edible kale.