The term “tall cabbage” refers to two distinct scenarios: specific cabbage varieties naturally bred for height, or standard cabbage plants that prematurely develop a tall flower stalk, a process known as bolting.
Understanding Tall Cabbage
The term “tall cabbage” can describe a plant intentionally bred for height, such as “Walking Stick Cabbage,” or it can signify bolting. Bolting is a condition where a typical cabbage plant, instead of forming a compact head, prematurely sends up a central stalk to produce flowers and seeds. This undesired growth is the plant’s natural response to stress, signaling a shift from vegetative growth to reproduction.
Naturally Tall Cabbage Varieties
Certain cabbage varieties are renowned for their impressive height, often grown for their unique characteristics rather than compact heads. The “Walking Stick Cabbage” (Brassica oleracea var. longata), also known as “Jersey Cabbage” or “Tree Cabbage,” is a notable example. Native to the Channel Islands, this plant can reach heights of 6 to 10 feet, with some specimens growing up to 18 to 20 feet in ideal conditions. Historically, its robust, fibrous stalks were dried and varnished to create actual walking sticks, with tens of thousands sold annually in the early 20th century. The leaves from these tall varieties were also historically used as animal fodder and are edible for human consumption, often compared to kale.
These plants are often biennial or short-lived perennials in warmer climates (USDA zones 7 and above) but are grown as annuals in cooler regions. They thrive in neutral soil (pH 6.5-7.0) with good drainage and benefit from organic compost. Regular weekly irrigation, about 2 inches of water, is necessary during the growing season, and staking the plant as it grows tall helps maintain its upright structure.
Why Cabbage Grows Tall (Bolting)
Cabbage plants are typically biennials, meant to produce a head in their first growing season and then flower and set seed in their second. Bolting occurs when the plant prematurely shifts its energy from leaf and head formation to producing a flower stalk. This often happens due to environmental stressors that trick the plant into believing its life cycle is ending, prompting it to reproduce quickly.
One primary cause is temperature fluctuation, particularly prolonged cold periods (35-45°F or 1.7-7.2°C) followed by warmer weather. This “cold conditioning” can trigger the plant to initiate flowering, especially if seedlings are exposed to low temperatures. Conversely, excessively hot temperatures can also induce bolting, causing the plant to rapidly produce flowers and seeds instead of developing a head. Other stressors include insufficient or inconsistent watering, which leads to water stress, and nutrient deficiencies. Overcrowded planting and incorrect planting times, such as sowing too late in the season, also contribute to bolting by increasing competition and exposing plants to suboptimal conditions.
Preventing and Managing Cabbage Bolting
Preventing cabbage from bolting involves creating stable growing conditions and choosing suitable varieties. Selecting “bolt-resistant” or “slow-bolting” cabbage varieties can significantly reduce bolting. Examples include ‘Spring Crisp’ and ‘One Kilo Slow Bolt’ for Napa cabbage, which are bred to withstand bolting triggers. Planting at the correct time is also important; cool-season cabbages thrive when planted in early spring or late summer, allowing them to mature before extreme heat arrives.
Consistent watering is crucial, as both drought and overwatering can stress plants and induce bolting. Aim for moist, well-drained soil, and consider using mulch to help regulate soil temperature and retain moisture. Proper spacing between plants prevents overcrowding, ensuring adequate airflow and nutrient availability, which reduces stress. Providing light shade during unexpected hot spells can also protect cool-season varieties from heat stress.
If a cabbage plant has already bolted, it will not form a compact head. However, the leaves are often still edible, though they may develop a bitter taste. You can harvest the outer leaves for consumption, but once the flowering stalk is prominent, it is best to remove the plant.