PlantFun
Plant Needs
Sunlight
Requires 6–8 hours of direct daily sunlight for proper head formation; tolerates partial shade in hot summer climates
Watering
Water deeply when the top 2–3 cm of soil dries out; avoid overhead watering to reduce fungal disease risk
Temperature
Hardy to -10°C for mature plants; optimal growth at 15–20°C; prolonged temperatures above 25°C trigger bolting
Characteristics
- Leaf: Dense, overlapping waxy leaves forming a compact head; outer leaves are larger, looser, and range from blue-green to purple.
- Stem: Short, thick central stem supporting the leaf head; elongates dramatically when the plant bolts.
- Flower: Small, four-petaled yellow flowers arranged in upright racemes during bolting.
Care Guide
Watering
Keep soil consistently moist during active head growth to prevent splitting
Fertilization
Apply balanced organic fertilizer at planting. Avoid over-fertilizing with nitrogen, which can promote leafy growth over head formation
Eggshell powder top-dress：Crush dried eggshells into fine powder; sprinkle 1–2 tbsp around base of plants and work into topsoil to boost calcium levelsPruning
- Remove outer yellowing or damaged leaves to improve airflow and reduce pest habitat
- Trim bolted flower stems immediately if not saving seed to redirect energy to head growth
- Thin overcrowded seedlings to 30–45 cm apart to allow sufficient space for head development
Toxicity
Warning: this plant may be toxic.
Pets & Humans
Pets: ASPCA: Non-toxic; no known adverse effects from ingestion
Humans: Non-toxic; widely cultivated as an edible vegetable
Garden Uses & Culture
Culture: N/A
Usage: Edible vegetable; used in salads, stir-fries, soups, and fermented dishes like sauerkraut
