Ornamental cabbage, a striking decorative plant, offers unique foliage that enhances patios, balconies, and entryways. Its vibrant, rosette-like leaves provide seasonal color, making it a popular choice for container gardening. While related to edible cabbages, these plants are primarily cultivated for their aesthetic appeal, often resembling large, colorful flowers rather than typical vegetables.
Selecting Pots and Soil
Choosing the appropriate container and potting medium is foundational for successful ornamental cabbage cultivation. Containers must feature ample drainage holes to prevent waterlogging, which can lead to root rot. Larger pots are beneficial as they help retain moisture and provide better insulation for the roots. An ideal potting mix for ornamental cabbage should be well-draining, fertile, and have a slightly acidic to neutral pH, typically ranging from 5.5 to 6.5. A general-purpose potting mix is suitable, and drainage can be enhanced by adding perlite or sand; garden soil should not be used in pots due to its tendency to compact and the potential introduction of pests or diseases.
Planting and Basic Care
Planting Steps
Planting ornamental cabbage involves a few straightforward steps. Gently remove the plant from its nursery container, taking care not to damage the root ball. Place the plant at the same depth it was in its original container, then backfill with potting mix, firming the soil around the base for support. Water the plant thoroughly after planting to help settle the soil.
Light Requirements
Ornamental cabbage thrives in full sun, requiring at least six hours of direct sunlight daily for optimal growth and vibrant color development. In warmer climates, providing partial afternoon shade can help prevent the plants from bolting, which is when they prematurely send up a flower stalk. While partial shade may slightly mute the leaf colors, it can extend the plant’s display period in hotter regions.
Watering
Consistent moisture is important for ornamental cabbage, but the soil should never be soggy. A good practice is to check the soil moisture regularly, watering when the top inch or two of the potting mix feels dry to the touch. Water the plant until excess water drains from the bottom of the pot, indicating that the entire root ball has been moistened. Potted plants generally dry out faster than those planted in the ground, so more frequent watering may be necessary.
Fertilizing
Ornamental cabbage is not considered a heavy feeder, but it benefits from appropriate nutrition. Applying a balanced, slow-release granular fertilizer at the time of planting can provide a steady supply of nutrients. Alternatively, a liquid feed can be applied every few weeks during periods of active growth, typically at a concentration of 150 to 200 ppm nitrogen. Over-fertilization can reduce the intensity of the plant’s colors and promote leggy growth, so moderation is advised.
Ensuring Vibrant Color and Longevity
Temperature and Color Development
The striking colors of ornamental cabbage intensify as temperatures cool, typically when ambient temperatures fall below 50°F (10°C). Nighttime temperatures consistently below 60°F (15°C) are particularly beneficial for color development, as cooler conditions suppress chlorophyll production and enhance the vibrant hues. While these plants can tolerate temperatures down to approximately 5°F (-15°C), extreme heat or prolonged warm temperatures can cause them to bolt or lose their color vibrancy.
Pest and Disease Management
Ornamental cabbage can be susceptible to common pests such as aphids, cabbage worms, flea beetles, and slugs. Manual removal of larger pests can be effective, and a strong spray of water can dislodge aphids. For more persistent infestations, insecticidal soaps or horticultural oils can be used. Common diseases include leaf spots, black rot, and root rot, often occurring in damp conditions. Ensuring good air circulation around the plants and proper drainage helps mitigate the risk of fungal diseases.
Extending Display
To prolong the visual appeal of ornamental cabbage in pots, regular maintenance is helpful. Removing any yellowing or damaged outer leaves not only improves the plant’s appearance but also directs energy to healthy foliage. In very cold regions, providing some shelter from harsh winter elements can extend their display, though they are generally resilient to light frosts and even some snow. Rotating pots periodically ensures that all sides of the plant receive even light exposure, promoting uniform growth and color development. Ornamental cabbage is typically grown as an annual and is often replaced with warm-season plants once temperatures rise.