How to Grow Ornamental Kale and Cabbage

Ornamental kale and cabbage, both varieties of Brassica oleracea, offer gardeners a striking way to add color and texture to landscapes during the cooler months. These plants develop vivid rosettes with centers in shades of pink, white, red, or purple, surrounded by textured outer leaves that range from smooth to deeply frilled. Unlike their edible counterparts, these are prized purely for aesthetics, thriving in full sun and cool temperatures to produce displays that intensify after frost.

Understanding the Unique Appeal of Ornamental Varieties

These cool-season stars belong to the Acephala group, meaning they form loose leaf rosettes rather than tight heads. Ornamental kale typically features curly, ruffled, or lobed leaves, while cabbage types have broader, flatter foliage with colorful edges or centers. Plants generally reach 12 to 18 inches in height and width, making them ideal for borders, containers, or mass plantings.

Cool weather below 50°F triggers pigment development, turning ordinary green foliage into a spectacle of fuchsia, rose, cream, and violet hues. They withstand temperatures down to 5°F once established, often persisting from fall into early spring in milder climates.

Best Times for Starting and Transplanting

Timing is crucial to avoid bolting, which occurs in heat. For fall displays, start seeds indoors in July or mid-summer, about 6-10 weeks before the first frost. Seeds need light exposure and temperatures in the upper 60s to 70°F for germination—press them lightly into moist soil without covering.

In cooler regions, direct sow in the garden or refrigerate seed pots briefly to mimic chill. Transplants from garden centers work best in warmer zones; plant them out when temperatures cool in early fall, such as late August to mid-September.

• Spring displays: Start seeds 8 weeks before last frost, but expect less vibrant color without sustained cool weather.
• Fall/winter shows: Ideal for most areas; colors peak as nights shorten and chill sets in.
• Zone considerations: In USDA 8a and similar, buy fall transplants to bypass summer heat.

Selecting the Perfect Site and Soil Preparation

Choose full sun locations with at least 6 hours of daily light for the richest colors. These plants demand moderately moist, fertile, well-drained soil rich in organic matter. Avoid waterlogged areas to prevent fungal issues.

Before planting, amend beds with 3-4 inches of compost or organic matter per 100 square feet. Incorporate 2 pounds of slow-release fertilizer (like 12-6-6) to support growth without excess nitrogen, which causes legginess.

Step-by-Step Planting Instructions

Opt for mature transplants for quicker results. Dig holes spaced 12-18 inches apart, burying stems so the lowest leaves touch the soil surface—this anchors plants against wind and frost.

1. Water transplants thoroughly before removal from pots to retain root balls.
2. Remove any yellowed lower leaves to promote airflow.
3. Position to showcase centers; rotate if needed for symmetry.
4. Firm soil around roots and water deeply to settle.
5. Apply 2-inch mulch layer for moisture retention and temperature stability.

In containers, use a central plant surrounded by low-growers for balanced pots. Ensure pots have drainage holes and use potting mix amended with compost.

Ongoing Maintenance for Peak Performance

Water consistently to keep soil evenly moist, especially in the first weeks post-planting. Once established, they tolerate dry spells but perform best with steady moisture—avoid overhead watering to minimize disease.

Fertilize sparingly; a single dose at planting suffices. Deadhead any flower stalks promptly to prolong foliage display. Pests like aphids or cabbage worms may appear—use insecticidal soaps or powders like Sevin on affected leaves.

These “kings of cold” improve post-frost, but pull when they develop a cabbage odor, signaling decline.

Creative Design Ideas and Companion Pairings

Versatile for any space, use in masses for bold drifts, edgings for crisp lines, or pots for patios. Front borders pair them with fall perennials like little bluestem grass (Schizachyrium scoparium), dark sedums, or asters.

• Containers: Center with pansies, petunias, snapdragons, or Swiss chard for frost-tolerant mixes.
• Beds: Fill gaps from faded summer annuals; group for impact.
• Indoors: Pot temporarily as table centerpieces before outdoor return.

Taller hybrids suit cut arrangements, while dwarfs fit small spaces. In mild areas, they overwinter as perennials.

Overcoming Common Challenges

Bolting from early heat or excess fertilizer ruins form—stick to cool planting. Fungal rots stem from poor drainage; ensure air circulation. Pests are manageable with vigilant checks.

In very cold zones, mulch heavily or use as annuals. Colors fade in prolonged warmth above 50°F, so site selection matters.

Frequently Asked Questions

Can ornamental kale and cabbage be eaten?

Technically yes, but they’re bred for looks, not taste—leaves may be tough or bitter. Enjoy visually instead.

How long do they last in the garden?

From planting in fall through winter, often until spring in zones 7+; they endure light snow and frosts.

Do they need full sun in all climates?

Yes, for best color; partial shade dulls hues.

What’s the difference between kale and cabbage types?

Kale has frilly leaves; cabbage broader, smoother ones—both form rosettes.

Can I grow them from seed successfully?

Absolutely, with proper cool starts; expect 6-10 weeks to transplant size.

Advanced Varieties and Regional Adaptations

Explore dwarfs for tight spaces or upright types for height. In southern zones, delay planting until true cool-down; northern gardeners can push into winter with protection.

Experiment with hybrids boasting deeper purples or multi-toned centers for modern twists on classics.