Gardening for You: Frilly centers of ornamental kale look like blossoms

Autumn’s oranges, yellows and rusts are being exchanged for holiday reds and greens, silvers and whites. Ornamental or flowering kales are attractive replacements for those spent blooms of fatigued autumn chrysanthemums.

Ornamental kale is often called flowering kale because its frilly centers resemble a blossom. Yet the centers are not blossoms, rather are rosettes of fancy leaves that resemble a flower.

As a cool-season crop in the Brassicaceae family, kale has terrific staying power in cold weather. Ornamental kale can survive temperatures down to 20° F.  The center rosette of leaves stays tightly bunched in cold weather.

Ornamental and edible kales are biennial with a growth habit that requires two seasons to flower. The vegetative growth phase usually occurs in the cool months while the reproductive growth phase kicks in when temperatures rise. The true flowers of kale are unattractive; small florets are borne on a tall, rank, woody flower stalk that emerges from the center of the plant in late winter or spring.

The center rosette of leaves is the eye-catching feature of ornamental kale. All leaves of ornamental kale have ruffled edges; even the oldest leaves are crinkled, but it is the puckered centermost leaves that develop into a frilly rosette pattern. The youngest leaves emerge from the center surrounded by oldest leaves and as more leaves develop the rosette is formed.

Young leaves of the developing rosette are green when they are first formed but when the rosette is subjected to cold temperatures a color change occurs. The green pigment chlorophyll degrades with a concomitant increase in white, pink, or purple pigments. Cold temperatures intensify colors.

Ornamental kale is often used as a specimen container plant, but it is effective when massed as a low-growing border specimen. Plant in well-drained potting soil; bury the thick taproot so that the lowest leaves are flush with the soil surface. 

To keep colors of the center rosette bright throughout the winter place in a sunny location that receives at least six hours of sunlight daily. Fertilize lightly with dilute nitrogen to keep the outermost leaves green; keep moist but not soggy wet.

Is ornamental kale edible? Yes, but be forewarned that ornamental kale has been bred for its showy colorful center rosettes, not for flavor as the vegetable kale. Leaves of ornamental kale are bitter and tough but may have a place at the table as a garnish.

Caution: Nursery-purchased ornamental kale may have been treated with chemicals. If leaves of ornamental kale are to be eaten be absolutely certain the plant has not been treated with a pesticide.

Ellen Peffley taught horticulture at the college level for 28 years, 25 of those at Texas Tech, during which time she developed two onion varieties. She is now the sole proprietor of From the Garden, a market garden farmette. You can email her at gardens@suddenlink.net