'Toy Choy' Bok Choi (Brassica chinensis L. 'Toy Choy') is a miniature, 5-inch tall bok choi (sometimes "pak choi") with white petioles and dark green leaves. The NGB says it's "perfect for home gardeners and specialty growers." It can be harvested 30-35 days from seed. Note: Bok choi is believed to be oldest of the Asian greens, having been cultivated in China since the 5th century.