The original wild cabbage, from which kale, collards, cabbage, broccoli and cauliflower crops were developed, still grows along the coasts of North Africa and Europe. Botanists, through hybridizing by cross-pollination, developed ornamental cabbages and kales and although they are still edible, are not as tasty and tender as their cousins.
They all make unusual additions to fresh flower arrangements, and the taller growing varieties are especially sought after by florists for their long stems.
In the Garden:
Because these showy cabbages can hold their brilliant colour all the way into spring, they are ideal for displaying on porches, patios, beside entryways, or for massing in garden beds. When massed in large beds they make a striking contrast to modern architecture. Be adventurous and try combining them with other seedlings in pots and window boxes.
Ornamental cabbages are grown as winter annuals in South Africa and seeds can be sown in autumn, or you can purchase trays of seedlings, or potted plants from your garden centre. They are easy to grow and hardy, even when the ground is frozen solid and the temperatures are way below freezing. Ornamental Cabbages should be planted in a sunny location, but they will take some shade. They prefer a moderately moist, rich soil; and because they can’t stand overly dry conditions, keep them well-watered, never allowing the soil to dry out completely, but be careful not to drown them either! Too much fertiliser can interfere with colour and cause stem elongation, so fertilising at planting time with a balanced granular fertiliser like 3:2:1 or 2:3:2 should be sufficient. The plants will grow about 20cm tall and 30cm wide, depending on the variety. Cut off the flower stems as soon as they appear.
Seeds are easily sown directly into garden beds or seedling trays in autumn, germinating best in soil temperatures between 18 and 21°C. The seeds require light for germination, so do not cover them with soil. Sow the seeds about six to ten weeks before the first anticipated frost so that your plants can acclimatise gradually to the cold. Ornamental cabbages are very hardy but a sudden cold- snap can be deadly to tiny plants. The seeds should germinate within 10 to 14 days and be in full-colour within 6 to 8 weeks after sowing.
Seedling trays or potted plants can be planted out anytime, but if you are planting out a bit late in the season, they must be gradually acclimatized to severe outdoor temperatures, or a sudden very cold snap could be deadly, especially for small plants. If you have planted out and suspect extreme weather, cover them with frost guard material until they are acclimatised.
When purchasing ornamental cabbages in pots, select plants with short stems. Generally, if these plants were allowed to become root bound in their pots, they will not get much larger after they are planted out, so it may pay in the long run to buy the biggest plants you can find, even though they may cost more. Plant the potted plants so the lowest leaves are flush with the ground.
Pests & Diseases:
Watch out for cabbage worms, harlequin bugs, slugs, grasshoppers, and cabbage aphids