Brassica rapa var. rosularis or Brassica narinosa
Tatsoi is one of the Asian greens, a type of Chinese cabbage. This quick growing cabbage doesn’t build a firm head. It forms a low growing rosette of small spoon shaped dark green leaves with short pale lime green stems. The leaves are the vegetable and are about 6 cm long. Tatsoi is high in vitamin A and vitamin C. If tatsoi goes to flower it shows the typical cross-shaped flower of the cabbage family with four petals.
How to grow:
Sow directly 3 mm deep in well drained and lightly fertilised soil where it’s supposed to grow. Sow in spots 20 cm apart. Put in 3 seeds per spot, 2 cm apart. Firm down and keep moist. Choose a sunny warm place. Plants appear within 6 to 10 days. Thin the plants to 2 and finally one plant per spot, 20 cm apart and mulch between the plants. Plants need to be watered consistently.
Doesn’t need much fertilising.
Harvest in 6 to 7 weeks.
Growing in the neighbourhood:
Likes to grow with lettuce, kale, endive, tatsoi, mizuna.
Pests and other problems and how we deal with them:
Caterpillars of butterflies, especially the white cabbage butterfly are pests on tatsoi. We keep them out by netting the bed with a 5-10 mm net as long as the plants are small. A bit of leaf loss on mature plants is tolerable, if caterpillars take away too much leaf material we spray the plants with a bacterial solution that controls them.
All members of the cabbage family can be affected by a single-celled organism deforming the roots and making it hard for the plants to take up water. The problem is called club root and requires serious soil treatment. We try to avoid this by strictly rotating crops.
All seasons, but fares better in cooler months.
Tatsoi cross pollinates with other plants of the cabbage family. In order to collect useful seeds the mother-plant would need to be kept isolated.
How to harvest and use:
Pick single outer leaves or harvest whole plant. The leaves are kept to be eaten, the roots at the bottom are taken to the compost.
Tatsoi leaves a great addition to salads. They can be used in stir fries and soups. Its peppery notes go well with citrus, apple and fennel. They also work well with garlic, ginger, mushrooms, soy sauce, seaweed, tofu and braised meat.