By the Middle Ages kale had spread throughout Europe and Asia. Early Roman manuscripts include references to “brassica,” a word that encompassed wild turnips, cabbages and kale-like plants. Historically kale has been particularly important in colder regions due to its resistance to frost, and in nineteenth century kale was grown as a staple crop in the Scottish Islands due to its extreme hardiness, and even fed to livestock through the winter. Kale was given some protection from the elements in purpose built ‘Kale Yards’. Indeed, almost every house had a kale yard and preserved kale in barrels of salt, similar to sauerkraut in Germany. Kale continued to be extremely important until potatoes came to the Islands at the end of the 18th century.
Kale continued to evolve, with the Italians developing plants with ‘scales’, the Scots creating leaves like frilly petticoats, and the Russians producing kale that could survive in the snow. Today there are countless varieties, some with large plain leaves and others with very curly or crimped foliage called “savoyed”. Varieties with savoy leaves have a finer texture than those with smooth leaves. The varieties also vary in their tolerance of cold and heat, with some growing better in warmer climates and others doing better in cold regions, so choose yours carefully.
Kale is low in calories, has zero fat, and is high in fibre, aiding in digestion and elimination. It has more iron than beef per calorie, and more calcium than milk per calorie. Iron is a mineral found in every cell of the body and essential because it is needed to make haemoglobin, a part of blood cells. Calcium aids in preventing bone loss, preventing osteoporosis and maintaining a healthy metabolism.
This wonderful vegetable is filled with powerful antioxidants such as carotenoids and flavonoids, helping protect against various cancers. The high Vitamin K content of kale also helps protect against various cancers. Vitamin K is also necessary for a wide variety of bodily functions including normal bone health and blood clotting. Increased levels of vitamin K can help people suffering from Alzheimer’s disease.
Kale is a great anti-inflammatory food, and one cup of kale has 10% of the RDA of omega-3 fatty acids, which help fight against arthritis, asthma and autoimmune disorders. Kale is also great for cardiovascular support and eating more kale can help lower cholesterol levels.
It is high in Vitamin A and Vitamin C. Vitamin A is great for your vision and your skin, and Vitamin C is very helpful for your immune system, your metabolism and hydration. Vitamin C is also helpful to maintain cartilage and joint flexibility. Kale is filled with so many nutrients, vitamins and minerals that anyone serious about their health would be advised to include it regularly in their diets.
Kale is used in cooking in much the same way as cabbage. The tender young leaves can be eaten raw and are wonderful in salads. More mature leaves are wonderful steamed, or cooked in soups and stews. Kale is a healthy addition to stir fries and can be substituted for spinach in omelettes, casseroles, or even quesadillas (wheat, flour or a corn tortilla’s which are filled with cheese. Often with other items added such as a savoury mixture of spices or vegetables.) Baked kale chips are delicious and the young leaves are also added to smoothies for their health-giving properties.
In the Garden:
When the weather warms, your kale plants will send up tall flower stalks with pretty, bright yellow flowers, making them very ornamental in the garden and you can cut the flowers for arrangements.
Petunias make excellent companions for kale and will act as a tonic plant. Grow kale together with table celery, celeriac, rosemary, sage and thyme, as these companion plants deter the cabbage moth. Table celery will help prevent grubs.
Cultivation and Harvesting:
Kale is a cool season crop that loves frost, and if established in late summer to autumn, the plants will continue to grow through winter. In cooler regions it can also do well if sown in early spring. Kale planted in late summer or early fall may sulk through spells of hot weather. Then, when conditions get colder the plants will take off, quickly multiplying in size. Kale prefers full sun but will tolerate semi-shade.
It grows so quickly that you can start harvesting from about 8 to 10 weeks after sowing. The outer leaves can be harvested as required or the whole plant harvested at once. If you harvest as needed, as the plants mature they will start to resemble small palm trees with stems and clusters of leaves on top.
Prepare the beds well in advance of sowing, adding compost, well-rotted manure and a dressing of organic 2:3:2. Kale prefers a pH of 6 to 7 and agricultural lime can be added to very acid soil. Seed is usually sown directly into the beds but can be raised in seedling trays and transplanted later. When sowing directly into beds sow the seeds in clumps or stations spaced about 30cm apart. When the seedlings are about 15cm tall, thin them out, leaving only the strongest plant. Kale is drought hardy once established but in order to produce good quality, flavoursome leaves, it requires plentiful and consistent moisture. Feed every three weeks with a balanced organic fertiliser that is high in nitrogen.
Being biennial, kale produces yellow flowers followed by elongated seedpods in its second year. Allow the seedpods to develop and dry on the plants to a tan colour before gathering them in a paper bag and breaking the pods open to collect the seeds. If stored in a cool, dry and dark place, kale seeds will store for up to three years. Be sure to work only with open-pollinated varieties when saving seeds, because hybrid varieties may not breed true from seed.
Pests & Diseases:
Kale grown in winter is generally a carefree crop, but as the weather warms up there are several insects that enjoy eating kale as much as people do. Watch out for velvety green cabbage worms chewing holes in the leaves. Also, for outbreaks of grey-green cabbage aphids, which often gather in clusters within the folds of frilly kale leaves. Treat small problems by spraying with an insecticidal soap and pick off and discard badly infested leaves. Towards the end of the growing season colourful black-and-orange harlequin bugs may show up on kale plants. Rather than fight the harlequins, most gardeners harvest the remainder of the crop and prepare the beds for the following harvest.
The information contained within this website is for educational purposes only, documenting the traditional uses of specific plants as recorded through history. Always seek advice from a medical practitioner before starting a home treatment programme.