Ornamental cabbage and kale look and grow very much like their close relatives of edible cabbages and kale. They are the same species, Brassica oleracea, and although they are still edible, they aren’t as tasty and tender as their cousins. They have been bred for looks, not flavor.
Although sometimes referred to as flowering cabbages, it’s the leaves that give the plants their color and interest as ornamentals. Rather than the usual green or purple of traditional cabbages, the leaves of ornamental cabbages and kale have been hybridized to feature rosy and/or creamy white colors, making them look more like large flowers than vegetables.
- Ornamental Cabbage: The plants with smooth leaf margins are considered flowering cabbage. The plant in the photo is an ornamental cabbage.
- Flowering Kale: Plants with serrated or fringed leaf margins are considered the flowering kales, which are further divided into the "fringed leaved cultivars" (those with ruffled leaves) and the "feather leaved cultivars" (those with more finely serrated leaves). These distinctions are not considered terribly important. The terms flowering cabbage and flowering kale are often used interchangeably.
Brassica oleracea species
Ornamental Cabbage or Flowering Kale
Just like their edible cousins, ornamental cabbage and kale or annuals. And like regular cabbage and kale, they are cool-season plants.
Mature Plant Size
Both ornamental cabbage and kale will grow approximately 18 inches tall and wide.
They will do fine in either full sun or partial shade. When grown in warmer climates, partial shade is preferable. Ornamental cabbages and kale don't develop their full colors unless they get a good chill from a frost.
It's the leaves that provide the "flowers" in ornamental cabbages and kale, so there is not waiting for them to bloom. If you are buying plants, they will probably already be mature and open, although the color will probably intensify as the temperature drops. If you are starting them from seed, give them about 11 to 14 weeks to reach full size. That means you will need to start them in late spring / early summer, for a fall planting.
Suggested Varieties to Grow
Unless you are growing commercially, there’s not that much variety to choose from. Most seed packets are simply labeled "Ornamental Cabbage". It’s best to just choose a color combination that appeals to you.
Using Ornamental Cabbage in Your Garden Design
Ornamental cabbage and kale look especially good in a large planting, where their color really stands out. Since they are low growers, you’ll often see them as edging plants, where their purplish hues blend in well with other fall colors. If you only want one or two plants, they look less out of place in containers, than they do scattered throughout a garden. In fact, they make nice, long-lasting replacement plants for spent summer containers.
Growing Tips for Ornamental Cabbage and Kale
Growing the ornamental versions is not much different from growing regular cabbage or kale. The main difference is you are growing the plants toward the end of the season, rather than at the beginning. And there will be fewer pests to contend with.
As with all Brassicas, ornamental cabbages and kales prefer to be grown in cool weather. Although you can plant them out at any time, the colorful pigmentation doesn't develop until after frost or prolonged cold weather. If you plant them too early in the fall or late summer, the plants will get leggy and remain green. Besides, early plantings will be susceptible to cabbage pests like cabbage loopers. These pests will disappear after frost.
When buying plants, opt for larger plants, even though you'll pay more. Once cabbages get root bound, the top portion becomes stunted. If this happens when they are small, they will never fill out the way you'd like. Look for plants with short stems and relatively uniform length leaves, no holes and at least a hint of color
Both cabbages and kale prefer a slightly acidic soil pH of about 5.8 to 6.5. They like to dry out slightly between watering but will suffer stress if left dry for prolonged periods.
Growing Ornamental Cabbage from Seed: Sow seeds 3-4 months before you need full-sized plants and at least 6-10 weeks before a frost is expected. If you start seeds in cell packs or flats, be sure to transplant to larger pots as soon as the first true leaves appear. You don’t want to risk them getting pot bound so young. If seedlings get leggy, you can replant up to the bottom of the cotyledons.
You could also simply direct seed your cabbages in the garden since the weather will be warm. Cover lightly with soil and keep the soil moist until germination. Seeds should sprout within one to two weeks. Thin to about 18 to 24 inches apart, when seedlings are three to four inches tall.
Caring for Your Ornamental Cabbage
Ornamental cabbages and kale can last throughout the winter, but their appearance depends a lot on the weather. Too hot and they will bolt to seed, too wet and harsh and they’ll look tattered. But since most pests are scarce in the cooler months, there aren’t too many problems to look out for.
Aphids seem to be the most persistent pests, although cabbage looper and leafroller are still active in some areas and powdery mildew can become a problem if the weather remains damp. Many animals find them as tempting as edible cabbages. This is more of a problem if the weather remains warm. By frost, most animals are getting ready to hibernate.