Brassica rapa var. rosularis

Tat Soi is a cool weather vegetable plant in the mustard family that is grown as a food crop. The genus name Brassica is Latin for cabbage.

This plant can be grown as a spring or fall crop in fertile, moist, well-drained soil in full sun by direct seeding or transplants. The prostrate varieties can withstand temperatures below zero and can be harvested during the winter. Protection from the summer heat is advised when grown for a fall crop.  Higher temperatures and lack of proper water can cause the plants to bolt.  That will cause the plant to produce its flower stems prematurely, leading to a poor harvest.

There are both upright and prostrate varieties with the leaves generally being very dark and shiny and either smooth or crinkly. The flavor is similar to bok choi and the plant can be harvested at various stages of growth from young leaves to a mature rosette.  The young leaves and small rosettes are crisp, thick and tender with a mild taste.  They are typically used in salads and stir-fry.  It is also used in preparing soups, or added to other dishes, such as pasta. 

The foliage of Tat Soi is attractive enough to be grown in the front border of a flower bed in addition to the edible garden.

Potential problems, insects and diseases: Slugs, snails, cutworms, and flea beetles can be a problem. See pests of crucifers to the left.