Ornamental cabbage and kale look and grow very much like their close relatives of edible cabbage and kale. Although they're categorized as the same species (Brassica oleracea) as the edible varieties and you could eat them, the ornamental versions have been bred for looks, not flavor. Their leaves feature purple, rose, and creamy white colors, making them look more like large flowers than vegetables.
Plants with smooth leaf margins and broad, flat leaves are called flowering cabbage. And plants with serrated or fringed leaf margins are considered flowering kale. (Technically, both are kale because kale forms rosettes while cabbage forms heads.) Ornamental cabbage and kale are cool-season biennials planted in the fall. This means they grow their vegetative leaves the first year and then send up flowers the second year that produce seeds before the plant dies. However, they're primarily treated as an annual for their showy foliage and then removed from the garden.
|Botanical Name||Brassica oleracea|
|Common Name||Ornamental cabbage, flowering kale|
|Mature Size||12 to 18 inches tall and wide|
|Sun Exposure||Full sun|
|Soil Type||Rich loam, medium moisture, well-draining|
|Soil pH||5.5 to 6.5|
|Bloom Time||Rarely flowers|
|Hardiness Zones||2 to 11 (as an annual)|
|Native Area||Southern and Western Europe|
How to Grow Ornamental Cabbage and Kale
Ornamental cabbage and kale look especially good in a large grouping or as edging for a garden bed, where their purplish hues blend well with other fall colors. Growing the ornamental versions is not much different from growing regular cabbage or kale. Wait until temperatures cool. If you plant them too early in the fall or late summer, the plants will get leggy and wilt.
If you are buying plants, the leaves will probably already be mature and open, though the color might intensify as the temperature drops. If you are starting them from seed, sow seeds indoors roughly six to 10 weeks before your projected first frost date, and plant the seedlings outside in the fall.
The plants prefer to grow in full sun. However, when grown in warmer climates, partial afternoon shade is ideal.
An organically rich, loamy soil that drains well is ideal for these plants. Both cabbage and kale prefer a slightly acidic soil pH of about 5.5 to 6.5.
Keep the plants well watered; they like soil that's consistently moist but not soggy. If the top inch of soil is dry, it's time to water. If your usual cool-weather climate includes rain, you probably won't have to water at all. But be prepared to add supplemental water during a dry spell.
Temperature and Humidity
Ornamental cabbage and kale don't develop their full colors unless they get a good chill from a frost. They can last throughout the winter, but their appearance depends a lot on the weather. If it's hot with long daylight exposure, they will bolt (send up a flower stalk and go to seed). And if it's very wet with harsh storms, they will look tattered. They can survive as long as temperatures remain above 5 degrees Fahrenheit. However, a sharp drop in temperature can damage or kill plants.
Moreover, humidity typically isn't an issue for these plants. But if the weather is damp and the plants don't have good air circulation, they might develop fungal diseases, which can appear as spots on the leaves.
Fertilize ornamental cabbage and kale only at planting time using a balanced fertilizer. Don't fertilize while they're growing, or they can lose color and get leggy.
Growing Ornamental Cabbage and Kale in Containers
If you only want one or two plants, they often look less out of place in containers rather than scattered throughout a garden. In fact, they make nice replacements for dying summer plants. Choose a container with ample drainage holes, and use an all-purpose potting mix. Nursery plants likely won't grow much larger than they are when you get them, so you typically won't have to worry about repotting into a bigger container.
Growing From Seeds
Sow seeds three to four months before you need full-size plants and at least six to 10 weeks before frost is expected. Place seeds on top of the soil, as they need light to germinate. If you start seeds in a cell pack (a tray that can hold many seedlings), be sure to transplant the seedlings into larger pots as soon as the second set of true leaves appear. Keep the seedlings cool, and place lights an inch or two above them to avoid legginess. Slowly acclimate them to outdoor conditions before planting the seedlings in the garden during the fall.
Varieties of Ornamental Cabbage and Kale
Unless you are growing commercially, there’s not much variety to choose from when it comes to ornamental cabbage and kale. Most seed packets are simply labeled "ornamental cabbage." So it's best to focus on a color combination that appeals to you. Flowering kales can be divided into "fringed-leaved cultivars" (those with ruffled leaves) and "feather-leaved cultivars" (those with finely serrated leaves).
Some varieties include:
- 'Chidori' flowering kale: This plant has very curly leaf edges with leaves that are purple, creamy white, or deep magenta.
- 'Color Up' ornamental cabbage: This grows upright with green leaves and centers of white, pink, or fuchsia.
- 'Osaka' cabbage: This ornamental cabbage has large, smooth leaves with center colors of pink, red, or white. The plant typically stays compact.
- 'Peacock' flowering kale: This plant looks more like its edible kale cousins, with loose growth and deeply serrated leaves in red, purple, or white.
- 'Pigeon' series: This variety has a flattened shape with red or white centers.