RARE --- Pak Choi - Extra Dwarf. Heirloom, Non-GMO. Annual. Brassica rapa (Chinensis group). Cool-warm season. This specialty pak choi variety is smaller than baby pak choi. It is similar to our Chinese Pak Choi and Dwarf Pak Choi varieties although smaller and more compact. This fast-growing variety has curled, glossy, dark green leaves with short, thick white petioles. Can be grown year round in sub-tropical areas.