Brassica oleracea: Flowering Kale, Ornamental Kale, Ornamental Cabbage

This Florida-Friendly Landscaping™ publication is part of a series originally written by Edward F. Gilman. Visit https://ffl.ifas.ufl.edu/ to learn more about creating and maintaining attractive landscapes that protect Florida's water resources and environment.

Introduction

Brassica oleracea is a very diverse species of plants in the crucifer family (Brassicaceae), which contains brussels sprouts, cauliflower, broccoli, collards, kale, and cabbage. Ornamental cabbage (within the Acephala group) belongs to this species and is a landscape plant that is generally grown for its showy leaves and aesthetic appeal in the landscape. It is a biennial plant but is generally treated as an annual. Ornamental cabbage leaves are displayed in loose, showy rosettes with veins prominently displayed on the underside of the leaf (Figure 1). Leaf coloration may be green, blue, white, pink, red, or multi-colored. Good coloration is brought on by temperatures below 60°F, hence the plant being used in the fall, winter, and spring (Figure 2). The leaves are waxy, with an undulated leaf margin, which adds texture to the plant (Figure 3). Ornamental cabbage leaves are technically edible, but cabbages in the Capitata group are the common varieties that are sold for consumption. Ornamental cabbage is dramatic in mass plantings, may be used as borders, or in containers or above-ground planters (Figure 4).

General Information

Scientific name: Brassica oleracea

Pronunciation: BRASS-ick-uh awl-lur-RAY-see

Common name(s): flowering kale, ornamental kale, flowering cabbage, ornamental cabbage

Family: Brassicaceae

Plant type: annual; biennial

USDA hardiness zones: all zones (Figures 5 and 6)

Planting month for zone 7: Oct; Feb; Mar

Planting month for zone 8: Nov; Dec

Planting month for zone 9: Dec; Jan; Feb

Planting month for zones 10 and 11: Dec; Jan; Feb

Origin: not native to North America

Uses: edging; attracts butterflies; mass planting; container; border

Availability: generally available in many areas within its hardiness range

Description

Height: 1 to 2 feet

Spread: 1 to 2 feet

Plant habit: round

Plant density: dense

Growth rate: moderate

Texture: coarse

Use and Management

Ornamental cabbage makes an excellent cool-season bedding plant in the fall and spring. Some dieback may occur in the coolest regions of the south and into north Florida in a very cold winter. It can be used throughout the winter in central and south Florida. Ornamental cabbage plants should be removed and replaced with more heat-tolerant bedding plants once they flower. The vibrant colors of ornamental cabbage make this plant very showy in a mass planting. It is also suitable for smaller groupings, container gardens, or borders in gardens. Caution should be taken not to locate this plant around livestock or horses, as plants in the Brassica genus are known to cause various issues if consumed in large quantities.

With warm temperatures in central and south Florida, some cultivars may not provide the showiness desirable of ornamental cabbage except in the winter. Ornamental cabbage is cold tolerant, but excessive cold can damage the leaves. Care should be taken to prevent frost damage. Cultivars with various leaf colorations and leaf margins, compact growth forms, and different textures are available.

Ornamental cabbage is propagated by seed.

Design Considerations

Ornamental cabbage is an ideal plant for fall and winter interest. Their large, rosette shape and vibrant colors (pinks, purples, creams, and greens) command attention. They are not subtle background plants. Use them intentionally where you want a pop of color and bold texture. Pair them with the delicate foliage of pansies and violas, the fine needles of dwarf juniper, or the wispy blades of ornamental grasses to highlight the unique form of each plant. They can be used in drifts or blocks to create a dramatic effect. The coarse, broad texture of ornamental cabbage contrasts beautifully with fine-textured plants. In addition, ornamental cabbage in a container can be a stunning focal point on a porch or patio.

Pests and Diseases

Pest issues include caterpillars (cause aesthetic damage to plants), aphids, and slugs. Disease issues include Alternaria leafspot, rot, club root, and blackleg. Ensure proper cultural conditions to promote plant health.