Collards and Kale 

Brassica oleracea (Acephala Group)

Kale and collards are similar in many respects, differing in little more than the forms of their leaves. They are, in effect, primitive cabbages that have been retained through thousands of years.


Although more highly developed forms, such as cauliflower, broccoli, and head cabbage, have been produced in the last two thousand years or so, the kales and collards have persisted, although primitive, because of their merits as garden vegetables.These leafy nonheading cabbages bear the Latin name Brassica oleracea variety acephala, the last term meaning "without a head." They have many names in many languages, as a result of their great antiquity and widespread use.


Kale is often called "borecole," and in America collards are sometimes called "sprouts." "Kale" is a Scottish word derived from coles or caulis, terms used by the Greeks and Romans in referring to the whole cabbagelike group of plants. The German word Kohl has the same origin.


"Collards" is a corruption of coleworts or colewyrts, Anglo-Saxon terms literally meaning "cabbage plants."The cabbagelike plants are native to the eastern Mediterranean or to Asia Minor. They have been in cultivation for so long, and have been so shifted about by prehistoric traders and migrating tribe, that it is not certain which of those two regions is the origin of the species.


The original "cabbage" was undoubtedly a nonheading kind with a prominent stalk or stem, and the kales and collards are not far removed from it.


Kale is a cold-hardy crop producing "greens" high in nutritive value. It not well adapted to hot weather. Varieties of kale "greens" are of two types. Scotch types have gray-green and very curled and crumpled leaves while Siberian types are blue-green and less curled. Both dwarf and tall types are available with the dwarf types being preferred. Collards are similar in nutritive value but much more tolerant of warm weather.

Gardeners appreciate its willingness to grow when and where other vegetables won't.





A healthy leaf vegetable which does best in reach well manured soil. Lower leaves of plants may be cut from time and cooked: Leaves left too long become course and bitter.






The most known and popular Sukuma Wiki. A strong plant which branches heavily. If the lower leaves are cut regularly this varieties continue to produce for a long time stretching into dry season. Ability to recover especially moisture stress.


COLLARD VARIETIES (approximately 60-80 days depending on planting date and variety).

KALE VARIETIES (approximately 50-60 days).

The kale family, botanically the genus Brassica, includes three species with leafy forms -- probably close to those of the original wildings -- that gardeners call kale: B. oleracea, the wild ancestor of cabbage, broccoli, brussels sprouts, kohlrabi, and cauliflower, is from the Atlantic and Mediterranean coasts of Europe. The B. o. Alboglabra group includes the white-flowered Chinese kale. It's native to Southeast Asia.








Growing kales and collards


Plant seed 0.5 inch deep. Use hot-water treated seed and fungicide treat seed to protect against several serious seed-borne diseases. Hot water seed treatments are very specific (122 F exactly, for 25 to 30 minutes; the wet seed then quickly cooled and dried).

Space plants 14 inches apart in all directions, or 12 inches apart in rows 2 feet apart. Most kales will grow into whatever space is provided, having larger leaves and thicker shoots as more room is available. Plants mature in 50 to 80 days.

Soil, water, nutrients

 Growing requirements are about the same as those for cabbage: fertile soil, neutral pH, plenty of calcium, and water as needed. Excess nitrogen will cause sappy, frost-sensitive tissues. Well-drained loams relatively high in organic matter are suitable for collards and kale. Cover crops may be turned under to maintain organic matter. The desirable pH is between 5.5-6.5. If the pH is too high, manganese is frequently unavailable which results in a chlorotic condition of the leaves. If the pH is too low, an application of lime is recommended.


The following recommendations are general. It is advisable to have a soil test done for each field to be planted.

Nitrogen: 60-100 (N) lb/acre (1/2 at planting and 1/2 at thinning)
Phosphorus: 80-120 (P205) lb/acre
Potassium: 60-120 (K20) lb/acre
Sulfur: 30-50 (S) lb/acre
Boron: 0-4 (B) lb/acre
Magnesium: As indicated by soil test (may need 60-120 lbs MgO per acre)
Copper, boron, and zinc - as indicated by soil test.


Maintain uniform soil moisture for tender growth and maximum use of soil nutrients. As much as 12-14 inches of water may be needed. Soil type does not affect the amount of total water needed, but does dictate frequency of water application. Lighter soils need more frequent water applications, but less water applied per application.

Pests and diseases

 Botrytis (head rot) and black rot are the only diseases we find in our location, though kale may contract other diseases that affect the Brassica genus in your area. Botrytis causes leaves and the growing point to break down during wet, cold weather. Black rot causes spotting on leaves before the plant is mature. Both diseases are seed-borne and spread by spores on the wind or in the soil.

Cabbage aphids can be troublesome to drought- or heat-stressed plants. Syrphid fly larvae are major aphid predators on kale. If these or ladybird beetles aren't doing the job, spray insecticidal soap.

If you find brassy-colored aphid "mummies," this is a sign that tiny parasitic wasps are aiding your efforts, and more of these beneficial wasps will soon hatch out of the parasitized aphids. Leave the mummies in place.

Health Benefits

Besides its good looks, flavor, and benefits to garden ecology, kale is good food. To get more protein from a green, you'd have to eat nettles; to get more calcium, you'd have to eat lamb's quarters; to get more iron, you'd have to eat amaranth or purslane; to get as much vitamin A, you'd have to eat dandelions. You can't get more vitamin C from any other leafy green. And don't forget the benefits of fiber, and the kale family's proven reputation for anti-cancer properties.

Sources of Kales and Collards

These two vegetables are the most widely grown in Kenya. The main areas growing them for commercial purposes are Kiambu and Nyandarua Districts. From here the vegetables are transported to Nairobi and Mombassa the major deficient areas.