Skip to content
June 24, 2010 / Malcolm Dalebö

Growing Kale

  • Kale or borecole is a form of cabbage (Brassica oleracea Acephala Group), green or purple, in which the central leaves do not form a head. 
  • It is considered to be closer to wild cabbage than most domesticated forms. 
  • The species Brassica oleracea contains a wide array of vegetables including broccoli, cauliflower, collard greens, and brussels sprouts. 
  • The cultivar group Acephala also includes spring greens and collard greens, which are extremely similar genetically.
  • Not only is Kale a tasty vegetable with a long cropping season but it is a very attractive vegetable as well. Many gardeners grow them in their borders purely for their ornamental value, especially over winter.
  • Kale is resistant to most pests and diseases and grows in almost any site and position. 
  • Seems to be a favourite of both the small and large Cabbage White butterflies, and their caterpillars can strip kale of all of its foliage. The only safe protection from this pest would seem to be to protect the young plants with butterfly-proof netting.
  • Tolerant of most conditions and maintenance-free once planted, kale is an excellent addition to any vegetable garden.
  • Unlike growing other cruciferous vegetables, growing kale is virtually effortless. 
  • Kale will grow well even in poor soil, and is generally untroubled by the many garden pests, such as cutworms and root maggots, that plague other brassicas. 
  • A cool weather crop, kale will tolerate freezing temperatures up to five degrees Fahrenheit (-15 degrees Celsius.) In fact, the flavour of tender baby leaves are enhanced by a few hard frosts. 
  • Although kale is more heat-tolerant than many other brassicas, gardeners in very hot climates will get the best flavor by growing kale very early in the spring or in late autumn.
  • Kale is considered to be a highly nutritious vegetable with powerful antioxidant properties; kale is considered to be anti-inflammatory.
  • Kale is very high in beta carotene, vitamin K, vitamin C, lutein, zeaxanthin, and reasonably rich in calcium. 
  • Because of its high vitamin K content, patients taking anti-coagulants such as warfarin are encouraged to avoid this food since it increases the vitamin K concentration in the blood.
  • Kale, as with broccoli and other brassicas, contains sulforaphane (particularly when chopped or minced), a chemical believed to have potent anti-cancer properties.
  • Until the end of the Middle Ages, kale was one of the most common green vegetables in all of Europe. 
  • Curly leafed varieties of cabbage already existed along with flat leafed varieties in Greece in the fourth century BC. These forms, which were referred to by the Romans as Sabellian kale, are considered to be the ancestors of modern kales. 
  • Today one may differentiate between varieties according to the low, intermediate, or high length of the stem, with varying leaf types. 
  • The leaf colours range from light green through green, dark green and violet-green to violet-brown. Russian kale was introduced into Canada (and then into the U.S.) by Russian traders in the 19th century.
  • During World War II, the cultivation of kale in the U.K. was encouraged by the Dig for Victory campaign. 
  • The vegetable was easy to grow and provided important nutrients to supplement those missing from a normal diet because of wartime rationing.
  • Kai-lan, a separate cultivar of Brassica oleracea much used in Chinese cuisine, is somewhat similar to kale in appearance and is occasionally called “kale” in English.
  • Kale Lutes can be classified by leaf type:
  1. Curly leaved (Scots Kale Lutes)
  2. Plain leaved
  3. Rape Kale Lutes
  4. Leaf and spear (a cross between curly leaved and plain leaved Kale Lutes)
  5. Cavolo nero (also known as black cabbage, Tuscan Kale Lutes, Lacinato and dinosaur Kale Lutes)
  6. Because Kale Lutes can grow well into winter, one variety of Rape Kale Lutes is called ‘Hungry Gap’, named after the period in winter in traditional agriculture when little could be harvested.
  • There is an ideal soil and site for Kale but rest assured, it will grow in almost all conditions, even part shade and sandy soils will produce a reasonable crop. 
  • For the ultimate crop, grow in a soil that was enriched with compost or manure the previous season.
  • Full sun is best but they will grow well in part shade.

  • With the exception of rape kale, sow the seeds in a seed bed around April to May time. 
  • The timing is not crucial because kale will germinate in temperatures as low as 5°C / 42°F and as high as 35°C / 95°F. That’s an enormous range for any vegetable.
  • Sow the kale seeds about 1.5cm (½in) deep in rows which are 22cm (9in) apart.
  • Germination will take about 10 days.
  • When the plant is about 22cm / 9in high and four leaves have developed (about 6 weeks after sowing) transplant them to their final positions.
  • They should be planted slightly deeper than they grew in the seed bed.
  • Spacings are 45cm  (18in) apart with rows the same distance apart.
  • Rape kale should be sown slightly late in the season, May to June is a good time. Sow them directly in their final position because they do not like to be transplanted.
  • Water regularly at least until the plants are well-established.
  • Almost no care is required because these are one of the strongest and most disease resistant of all vegetables.
  • Remove yellowing leaves which will appear round the base of plant.
  • Keep the weeds under control with regular hoeing.
  • Dwarf varieties of kale will withstand winter winds especially well.
  • Begin to harvest your kale as soon as the leaves reach about six to eight inches (15 to 20 cm) in length. 
  • Harvest kale only when you need it because it does not keep well even in the fridge.
  • They provide a crop between late September to early May, although rape kale is at its best in spring.
  • Harvest the young leaves only which will be at the top of the plant. This will stimulate the plant to produce more young tender leaves.
  • Kale freezes well and actually tastes sweeter and more flavourful after being exposed to a frost.
  • Tender kale greens can provide an intense addition to salads, particularly when combined with other such strongly-flavoured ingredients as dry-roasted peanuts, tamari-roasted almonds, red pepper flakes, or an Asian-style dressing.
  • In the Netherlands it is very frequently used in the winter dish stamppot and seen as one of the country’s traditional dishes, called Boerenkool.
  • In Ireland kale is mixed with mashed potatoes to make the traditional dish colcannon. It is popular on Halloween when it is sometimes served with sausages. Small coins are sometimes hidden inside as prizes.
  • A traditional Portuguese soup, caldo verde, combines pureed potatoes, diced kale, olive oil, broth, and, generally, sliced cooked spicy sausage. 
  • Under the name of couve, kale is also popular in Brazil, in caldo verde, or as a vegetable dish, often cooked with carne seca (shredded dried beef). 
  • When chopped and stir-fried, couve accompanies Brazil’s national dish, feijoada.
  • In East Africa, it is an essential ingredient in making a stew for ugali, which is almost always eaten with kale. 
  • Kale is also eaten throughout southeastern Africa, where it is typically boiled with coconut milk and ground peanuts and is served with rice or boiled cornmeal.
  • A whole culture around kale has developed in north-western Germany around the towns of Bremen, Oldenburg and Hannover as well as in the State of Schleswig-Holstein. There, most social clubs of any kind will have a Grünkohlfahrt (“kale tour”) sometime between October and February, visiting a country inn to consume large quantities of boiled kale, Kassler, Mettwurst and schnapps. These tours are often combined with a game of Boßeln. Most communities in the area have a yearly kale festival which includes naming a “kale king” (or queen).
  • Curly kale is used in Denmark and Halland, Sweden, to make (grøn-)langkål, an obligatory dish on the julbord in the region, and is commonly served together with the Christmas ham (Sweden, Halland). The kale is used to make a stew of minced boiled kale, stock, cream, pepper and salt that is simmered together slowly for a few hours. 
  • In Scotland, kale provided such a base for a traditional diet that the word in dialect Scots is synonymous with food. To be “off one’s kail” is to feel too ill to eat.
  • In Montenegro collards, locally konwn as rashtan is a favorite vegetable. It is particularly popular in winter, cooked with smoked mutton (kastradina) and potatoes.
  • Kale is a very good source of iron, calcium, vitamin C, vitamin K and Carotenoids (which provide vitamin A). 
  • In Japan, kale juice (known as aojiru) is a popular dietary supplement.


Leave a Comment
  1. Anonymous / Jun 25 2010 1:05 pm

    Ref Kale being resistant to common pests.I grow leaf-and-shoot variety 'Pentland Brig'.The Cabbage White butterflies, both 'Large' and 'Small' varieties seem to prefer Kale to my cabbages!Strips it bare if not protected by fine butterfly-proof netting.Love your site,Martin, Droitwich.

  2. Malcolm Dalebö / Jun 26 2010 10:18 pm

    Thanks Martin, I have modified the posting to reflect your experiences.Glad that you like the site, any other contributions will be welcome as I want to get it as informative as possible.Regards, Malcolm

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: