Brassica rapa narinosa
This species has been cultivated as a food crop for many hundreds of years and, in that time, several quite distinct forms have arisen. The nomenclature of these forms is confused, to say the least, and by no means universally accepted. We have followed the treatment used by GRIN, though it is very likely to be revised in the future[
Brassica campestris narinosa (L.H.Bailey) Kitam.
Brassica narinosa L.H.Bailey
Common Name: Chinese Savoy
Tat soi is an annual to biennial plant developed in cultivation from Brassica rapa. Growing from a non-fleshy taproot, it forms a rosette of spreading leaves and, eventually, a flowering stem up to 100cm tall.
Tat soi is often cultivated, especially in the Orient, for its edible leaves.
The oil contained in the seed of some varieties of this species can be rich in erucic acid which is toxic. However, modern cultivars have been selected which are almost free of erucic acid.
A cultivar of garden origin
Not known in the wild.
Tatsoi has been developed in cultivation in the warm temperate zone of China. It can be grown as an annual from the temperate zone to the tropics and can also be grown in the cold season in the temperate zone, where it can tolerate temperatures down to around -10°c and can even be harvested from under the snow.
Succeeds in full sun in a well-drained fertile preferably alkaline soil[
]. Prefers a pH of 5.5 - 7[
]. Tolerates a pH in the range 4.3 to 7.5. Prefers a cool moist reasonably fertile soil[
There are some named varieties.
Leaves - raw or cooked.
Seed - sow in situ in the spring and early summer.