The leafy green cabbage has been a highly nutritious option for millennia, rich in vitamin C, fibre and vitamin K. Some research suggests that it may have health benefits that include supporting digestion and heart health, among others.

One unique, attractive and relatively new variant of the leafy green is the red cabbage. Scientifically known as Brassica oleracea var. capitata f. rubra and belonging to the Brassicaceae family, this variety of cabbage is also referred to as purple cabbage due to its purplish-red leaves.

OLD WIVES’ TALE

Historically, this variant finds its documented roots in the Middle Ages and was a well-known vegetable in European countries around a thousand years ago. Traditionally, the vegetable was even used in predicting the gender of the baby-to-be during pregnancy. Many still believe it works.

The process is simple. Water is boiled and in it is added the urine of the pregnant woman, later a certain amount of red cabbage juice is added to the mixture. If the colour of the mixture changes to pink or red, it is assumed that the developing baby is male. In case, the mixture turns more purplish or blue, it is believed that the family is going to be blessed with a baby girl.

A favourite since mediaeval times, the red cabbage offers numerous health benefits, but only if you avoid common planting pitfalls…

This test works because of pH levels. The cabbage water is neutral, while the urine during pregnancy can have different pH levels, based on gender, but not always. Medical experts have shied away from stating their opinions with regard to the cabbage gender test. Many doctors have stated that there is a big difference in pH levels across all women, particularly when they are pregnant, which is a factor that can either fade or leave cabbage water purple. Therefore, an ultrasound appears to be the preferred way of determining the gender of a baby. 

DEFINING FEATURES

The reason for the cabbage being red in colour is the presence of a pigment known as anthocyanin. This pigment is responsible for the characteristic red, blue and purple colours in different vegetables and fruits, especially different types of berries. Anthocyanin accounts for more of a purplish to blue colour in neutral to increased pH (more alkaline) but in lower (acidic) pH, it comes up with the red shade.

The plants of the red cabbage are also different. The outer leaves of the plant are purplish to grey in colour. The inner, comparatively smaller, head of the red cabbage is made up of a few shades, ranging from light pink to even dark maroon. This makes the red cabbage plant a beautiful proposition for gardeners.

The seeds of the red cabbage are almost identical to those of the green cabbage and, similar to them, they should not be sown deep into the soil. The seeds are smaller in size and round in shape, while being harder compared to the seeds of other vegetables. The colour of the seeds may range from dark brown to black.

While preparing the soil for sowing, it should be ensured that there are no stones or pebbles present in the potting mix. Nursery soil can be used for sowing seeds. The relatively smaller-sized seeds of the red cabbage have the tendency to shift away from their original sowing positions, if watered afterwards. Therefore, it is better to water the soil beforehand.

The soil should also be properly drained, sans water pockets. In case of water pockets, the health of the seeds and roots may take a drastic hit, due to root rot and other diseases and infections. The soil content can be boosted with a thin layer of compost, either mixed within or sprinkled on the surface after sowing the seeds.

Seeds should ideally be sown in the temperature range of 18 to 22 degrees Celsius. Late October is the ideal time to sow the seeds for those living in Karachi. It corresponds to the time where summers gradually start to fade away.

One may sow one seed of red cabbage in each cell of the seedling tray, a few seeds in a paper cup or four to five seeds in a four-inch container. The intention is to shift the stronger seedlings to their permanent place later. The seed-sowing container should be covered with plastic and placed in a cool place under shade, to minimise evaporation from the soil surface.

Please send your queries and emails to doctree101@hotmail.com. The writer is a physician and a host for the YouTube channel ‘DocTree Gardening’ promoting organic kitchen gardening

Published in Dawn, EOS, August 24th, 2025