Kale is a winter vegetable and belongs to the cabbage family. It is very hardy and is able to withstand the severest of winters, producing plenty of tops for use during January, February, March and early April.
This plant will grow in the poorest of soils but responds favourably to richer soil high in nutrients, and seems not to be troubled by diseases which strike many other winter growing vegetables, especially clubroot, which attacks brassicas generally; however good drainage is necessary.
If you plant early in the year, consider using raised beds to allow better drainage during the winter months. Kale can be planted out after early potatoes or peas without any adding extra fertilizers, however, if the soil is particularly poor, rake in some fish manure at 2 oz. (60g) to the sq. yd.
It depends on the variety you are sowing as to the time the seeds should be sown, some are sown early during May or June whilst others are sown later in July and August, but generally, they are sown in June and July just as many early crops are harvested and the land becomes vacant.
Start your spring crop indoors four to six weeks before planting them outdoors. Plan to plant your seedlings outdoors very early in the season and after the last frost date for your area.
Plant seeds in containers ½ in. (12mm) deep in sterile starting mix. Water thoroughly once, then lightly after the seeds have sprouted. Provide plenty of sunlight or artificial grow lights so the plants do not become spindly. Boost your plant’s health with a light application of liquid fertilizer once or twice during this period.
Seeds can be direct sowed into the row or seeded in a separate area and transplanted to the row after a few weeks. If the seeds are planted together in a seedbed they can be later transplanted into the position where they are to mature and you can then better control the spacing.
If you are sowing directly where the Kale is to grow, sow in drills 1 in. (25mm) deep the drills being 2-½ ft. (75cm) apart, putting in three seeds every 2 ft. (60cm) along the drill. Later the seedlings can be thinned out only allowing the strongest one to remain in each station.
Whether direct seeding or transplanting, make the final spacing 18 to 24 inches (45cm-60cm) apart; the outer leaves of a healthy plant will spread and cover a lot of space.
Keep down the weeds with a hoe. In dry weather make sure that the vegetable has enough water to make good growth, this is particularly important during the late summer.
All members of the cabbage family are extremely susceptible to insects. Kale is no exception. Among the most common are aphids, and cabbage loopers, cabbage loopers the larval stage of a moth. Effective treatment is to place a screen over the plant so the moth cannot lay her eggs. Aphids should be sprayed with a garlic wash to deter them from penetrating the leaves.
Kale should be left to grow unrestricted until it is ready to harvest about the middle of January. Cut out the centre of each plant, which will then encourage the development of side growths. This will provide plenty of leaf until the end of April. Like the other Brassicas, kale’s leaves become much sweeter after experiencing a good frost.