Once cold weather settles in, choices for containers and seasonal displays are not overwhelming. Pansies and violas come to mind, a few choice perennials like euphorbia, heucheras and carex are also popular. One cold season vegetable seems to get no respect, yet give amazing color and cold tolerance, I'm referring to the ornamental kale and cabbage. Technically known as Brassica oleracae var. acephala, or simply brassica, which is the classical Latin name for cabbage. Members of the family produce flowers, although we refer to them as flowering kale and cabbage, in reference to the pretty foliage. In the mustard family, brassicaceae contain almost 4,000 species of plants, with a few ornamental members, actually grown for their flowers, like iberis or candytuft and honesty or the money plant (Lunaria annua).
The cabbage family originated in the Mediterranean region. Travelers and explorers carried seed to other parts of the world and records show that varieties of kale have been grown for thousands of years. The word kale is Scottish, adapted from the Roman name "cole". Popular in Scotland and China, a staple in their diet.
It is the Japanese that hybridized solely for ornament. Howard Dorsett, an astute employee of the U.S. Department of Agriculture discovered the ornamental kales in Japan in 1929. Plants first appeared in catalogs in 1936, their initial introduction into this country and first opportunity for garden testing. Not intended to be used as vegetables, if they do make it to the plate, it is simply as a garnish. Out of doors, in pot or garden, they do best when temperatures fall below 50 degrees. The foliage becomes more colorful with centers of white, pink, or purple. In protected areas, where temperatures do not fall below 15 degrees, they can remain all winter, particularly the kale.
Certainly not perfect, before a killing frost or freeze they can be eaten by the cabbage looper, a small green worm that can skeletonize the leaves. I generally pick them off, it's the simplest way. Warm temperatures will cause the stems to elongate, another reason to buy them when cool temperatures are the norm. Growers spray them with a growth retardant, not something the home owner can or will do.
The arrival of 'Redbor' kale elevated the whole group to new heights. Purple foliage gets darker as temperatures drop and it's highly likely that it will over winter, even putting up a nice display of yellow flowers in spring. I love to plant them with peonies since they flower together. The ornamental cabbage can be stunning as the centers turn bright colors while more tender plants go dormant or fade away. Matching them with pansies really is the perfect solution when you want just a bit more for fall and early winter.