For ‘cut and come again’ crops sow seeds in wide drills or broadcast, 6-12mm deep, thinning to leave 2.5cm between plants.
For small plants sow seeds in wide drills or broadcast, 6-12mm deep, thinning to leave space 2in (5cm) between plants.
For larger plants space 25-45cm (10-18in) apart, in and between rows.
Sow every month for continuous supplies.
Spacing of crops growing to maturity depends on the variety and speed of growth; plants being harvested at other stages of growth can be spaced accordingly.
‘Thinnings’ can be eaten at any stage.
Sow in early spring under cover, from late spring outdoors and late autumn under cover.
Komatsuna needs an open, sunny site and rich, fertile, moisture retentive soil; incorporate well rotted organic matter if necessary, before planting.
Add fertiliser such as Growmore before sowing if soil is not too rich.
Keep the soil consistently moist; water well during dry and hot periods.
Feed occasionally with general liquid fertiliser.
Although it can survive to down to – 14C, protecting with fleece can exclude light frost and improves the quality of growth.
Keep the soil moist and weed free.
Harvesting can start from around 30 days after sowing.
At any time from when the plants are 10cm (4in) high, cut them about 2.5cm (1in) above ground level so that plants can re-shoot to produce further crops.
Up to three cuttings per plant can be harvested over several months. Or you can cut leaves as and when you need them.
‘Red Komatsuna’: Ideal as micro or baby greens, the flat, round leaves are tinted red above and green with red veins below. Heat tolerant. Sow spring to autumn.
‘Green Boy’: This is sometimes listed as a form of ‘Pak Choi’. Heat tolerant with dark green leaves and thick leaf stems.
‘Nozawana’: Highly cold and heat tolerant with long green leaves. Popular in Japan for pickling.
Birds: Can be a problem as they will eat the leaves as they develop.
Remedy: Cover young plants with netting or fleece.
Bolting: Plants flower and set seed, rather than producing edible roots. This is usually caused by stress usually drought.
Remedy: Sow bolting resistant varieties, warm the soil before sowing early crops, grow under the protection of fleece or cloches and keep the soil moist.
More information on bolting
Flea beetle: This is a tiny insect pest mainly of brassicas. Beetles will eat small holes in leaves which turn brown. Seedlings are particularly susceptible.
Remedy: Grow under horticultural fleece, keep the soil moist.
More on flea beetle