General
These cool-season vegetables are incredibly easy to grow and very tasty. The leaves can be used raw in salads, but the whole plant can be steamed or stir-fried. Both types require regular watering and a watchful grower - plant repeated short rows, and be sure to harvest them before they bolt.
Latin
Brassica rapa chinensis
Family: Brassicaceae
Difficulty
Easy
Season & Zone
Season: Cool season
Exposure: Full sun to partial shade
Zone: 4-10
Timing
All are cool season plants that grow quickly and then bolt. Direct sow with frost protection (a cloche or heavy row cover) as early as February, or without protection from early March to late May. Sowing short rows every 2-3 weeks allows for a fairly constant harvest time. Sow again in August and September, and provide frost protection by the end of October.
Starting
Sow 3-4 seeds 5m-1cm (¼-½") deep in each spot you want a plant to grow. Thin to the strongest plant at a spacing of 15-20cm (6-6") between plants in rows 30-45cm (12-18") apart.
Growing
Ideal pH: 6.0-6.8. 1 cup of complete organic fertilizer will provide sufficient nutrition to 3m (10') of row. Choi Sum is harvested just before it flowers, so keep a close watch on each row. Pac Choi can be harvested at any stage, but if you want full-sized plants, watch for signs of bolting. Flower buds will appear at the centre of each plant, and a stem will form quickly as the plant turns from urn-shaped into a tall cone. Harvest as quickly as possible once flower buds are visible. Keep plants well-watered throughout their growth.
Harvest
Use a sharp knife to cut the plants at ground level when they are ready to harvest. They will not grow back like some other crops, so plant several short rows every couple of weeks for a longer harvest.
Seed Info
In optimal conditions at least 70% of seeds will germinate. Usual seed life: 3 years. Per 100' row: 260 seeds, per acre: 114M seeds.
Diseases & Pests
Slugs and woodlice (sow bugs) may nibble young seedlings. Keep the garden free from debris and excess water, where both of these pests like to go during the day. Protect plants from flea beetles and cabbage moths with lightweight row cover.
