Savoy cabbage (Brassica oleracea var. sabauda) is distinguished by its deeply crinkled, or savoyed, leaves and a looser head formation. This variety is prized for its more tender texture and milder, sweeter flavor compared to standard green cabbage, especially after exposure to light frost. It is a cool-weather biennial plant typically grown as an annual crop, thriving in moderate temperatures for optimal head development.
Site Selection and Initial Planting
Savoy cabbage requires a minimum of six to eight hours of direct sunlight each day to promote the development of a dense, healthy head. While it prefers temperatures between 60°F and 70°F, it is tolerant of light frosts, making spring and fall the optimal planting seasons for this cool-season crop.
The soil must be well-drained, fertile, and rich in organic matter, as Savoy cabbage is considered a heavy feeder. A loamy soil texture is ideal, and the soil pH should be slightly acidic to neutral, ideally maintained between 6.0 and 7.5 to discourage common brassica diseases like clubroot. Amending the planting area with generous amounts of compost or well-rotted manure before planting helps ensure adequate nutrition and improves drainage.
Most gardeners start seeds indoors four to six weeks before the last expected spring frost, transplanting healthy seedlings when they are about four to six inches tall. Seedlings must be hardened off by gradually exposing them to outdoor conditions over a week before permanent planting. Proper spacing is necessary for head formation; plants should be set 12 to 18 inches apart to allow for sufficient airflow and prevent disease.
Ongoing Care Requirements
Consistent and deep watering is required for Savoy cabbage, particularly when the head begins to form, as drought can cause the flavor to become bitter or prevent head development. The soil should be thoroughly wetted to a depth of at least six inches after each watering session. Allowing the top half-inch of soil to dry slightly between waterings prevents fungal issues associated with overly saturated conditions.
Savoy cabbage requires routine fertilization to sustain its rapid vegetative growth. A slow-release, balanced organic fertilizer is beneficial at planting, followed by applications of a nitrogen-rich fertilizer once the plants have developed four to five true leaves. Nitrogen fuels leaf and stalk production in the early stages. Avoid excessive fertilization, as too much nitrogen can delay maturity and cause excessive leafy growth instead of a tight head.
Applying a layer of organic mulch, such as straw or shredded leaves, around the plants is recommended. Mulch retains soil moisture, stabilizing the plant’s water supply, and regulates soil temperature. This layer also suppresses weed growth, preventing competition for nutrients and water.
Managing Common Pests and Diseases
Savoy cabbage is susceptible to specific pests and diseases. The most common insect threats include the imported cabbage worm, the cabbage looper, and the cabbage aphid. Cabbage worms and loopers are caterpillars that chew holes in the leaves. Aphids are tiny, sap-sucking insects that cluster on the undersides of leaves and excrete a sticky honeydew.
Non-chemical control methods are the safest initial approach for managing these pests. Physical barriers, such as lightweight floating row covers, are effective when placed over seedlings, preventing adult butterflies and moths from laying eggs. Hand-picking caterpillars is a simple method for low-level infestations, and a strong jet of water can dislodge aphid colonies. Introducing natural predators, such as ladybugs or parasitic wasps, provides long-term biological management.
Diseases like clubroot and black rot are managed through preventative cultural practices. Clubroot, a soil-borne fungus, causes swollen, distorted roots and is associated with acidic soil conditions. Maintaining a soil pH between 6.5 and 6.8 by adding agricultural lime helps suppress this disease. Black rot is a bacterial disease that causes V-shaped yellow lesions on leaf margins and is spread by water and contaminated debris. Practicing strict crop rotation, where no member of the cabbage family is planted in the same spot for at least two years, disrupts the life cycle of soil-borne pathogens.
Harvesting and Keeping Savoy Cabbage Fresh
Savoy cabbage is ready for harvest when the head feels firm and solid to the touch, typically between 90 and 120 days after transplanting. While the ruffled leaves can make the head feel slightly less dense than smooth-leafed varieties, a definite firmness should be present when compressed gently. Harvesting should happen before the head becomes overripe, which is indicated by the head splitting open and making the internal tissue vulnerable to decay.
To harvest, use a sharp, clean knife to cut the stem cleanly just below the lowest set of leaves, which hold the head together. Leaving the stalk and a few outer leaves in the ground may encourage the formation of several smaller, secondary heads. These side shoots offer a bonus harvest and a continuation of the season’s yield.
For short-term preservation, the harvested head should be stored in a cool, dark location, ideally refrigerated. Placing the head in a plastic bag or container helps maintain high humidity, preventing wilting and keeping the cabbage fresh for several weeks. Savoy cabbage is hardy and can often be left in the garden into late fall or early winter, as cool weather enhances its natural sweetness.