Brassica oleracea var. alboglabra. Chinese broccoli is also known as kailan. Grow Midwater Gai Lan Chinese broccoli seeds for a thick flower stalk 1-2cm (½-¾") that is used in stir-fries. Harvest the mild thickened stalk with 2 sets of leaves just as buds form but before the white flowers open. Each plant can be harvested several times. Sow around mid-March (4 weeks before last frost) or transplant when seedlings are 3-4 weeks old. Space plants about 20 x 40cm (8 x 16") apart. Buds and stalks are more substantial than Choi Sum. Best planted in spring and mid-summer.