What is Chinese cabbage (Brassica rapa ssp. chinensis)? It is sometimes
confused with a well-known Chinese leaves(Brassica rapa ssp.
Pekinensis). Green and white pak choi, choi sum are fast growing and can
ready for harvest in as little as 4-7 weeks. Chinensis varieties do not
form heads; instead, they have smooth, dark green leaf blades forming a
cluster. The texture of both leaves and stalks is crisp, and the flavour is
somewhere between mild cabbage and spinach.