Brassica rapa var. perviridis
Komatsuna
Common names: Japanese mustard spinach
At a glance
- Light
- Partial shade
- Spacing
- 15 cm, rows 25 cm
- Lifespan
- Annual
- Sowing
- Mar–Sep
- Harvest
- May–Nov
- Hardiness
- Cold damage below −8 °C
- Water need
- Medium
Photo: 日陰猫Joga at Japanese Wikipedia · CC BY-SA 3.0 · Source
This description was machine-translated.
Description
Komatsuna, botanically Brassica rapa var. perviridis, is a Japanese leafy vegetable. It does not form a head but a loose, upright rosette of glossy, dark green leaves on pale green, crisp stalks, growing about 25 to 30 cm tall. It can be harvested four to six weeks after sowing. The flavor is mild, between spinach and cabbage, with a faint mustard-like note. Young leaves can be eaten raw in salads, while larger leaves are best briefly steamed, stir-fried in a wok, or added to soups. In the garden, komatsuna is one of the easiest Asian vegetables. It tolerates cold down to about minus 8 °C, can be resown repeatedly from March to September, and grows in garden beds, raised beds, and balcony boxes.
Care instructions
Sow komatsuna directly into the bed from March onward, about 1 cm deep in rows 25 cm apart, and later thin the seedlings to 15 cm. For baby leaves, you may sow more densely. Sun or partial shade suits it well. In midsummer, a spot with afternoon shade is better, as the plant bolts more slowly there. Keep the soil evenly moist, otherwise the leaves become tough and sharp. The main pest is flea beetles, which chew small holes in leaves during dry weather. A fine-mesh insect protection net placed right after sowing keeps them away. Pick the outer leaves first so the plant keeps growing, or cut the plant 3 cm above the soil, after which it often sprouts again. Resow every three to four weeks to have fresh leaves until autumn.
The care notes were machine-translated from German.
Garden year
SowingMar–Sep
HarvestMay–Nov
Germination
- Soil temperature
- from 5 °C, ideally 20 °C
- Days to sprout
- 3 to 7 days
- Light
- Sprouts in light or dark
- Sowing depth
- 1 cm
- How to start
- Sow straight into the bed
Soil & site
Soil pH
Soil type
humus-rich, loamy, well-drained, nutrient-rich
Komatsuna grows in almost any garden soil, but best in loose, humus-rich and evenly fresh soil. Loamy soil holds water and nutrients well; on sandy plots, work in compost beforehand. The pH should not be too acidic, because clubroot spreads more easily on acidic soils. It does not tolerate waterlogging; loosen compacted beds thoroughly before sowing.
Komatsuna belongs to the crucifers and shares clubroot, cabbage root fly and flea beetles with cabbage, radish, mustard and rocket. Plan at least a four-year break on the same bed after any crucifers; green manures of white mustard or oilseed radish count too.
Feeding
Medium feeder
Months
Mar, Apr, Aug
Komatsuna is ready to harvest quickly and gets by with little fertiliser. Before sowing, work some mature compost shallowly into the soil; that is usually enough for the whole crop. For successive sowings in the same bed, a thin layer of compost is enough. If the leaves look pale, give diluted nettle liquid feed once. You are better off skipping fresh manure; it is too strong for such a fast leafy vegetable.
Overwintering
Komatsuna is an annual, but tolerates frost down to about minus 8 °C and can therefore be harvested into November. Protect late sowings from September with horticultural fleece or a polytunnel; in mild locations the plants survive the winter and put out growth once more in spring before they flower. In harder, prolonged frost they die. Remains go on the compost in spring, and the bed is then free for the next crop.
Propagation
Methods
- From seed
You propagate komatsuna from seeds, which germinate within a few days even at cool temperatures. Sow directly in the bed from March to September, cover the seeds with about 1 cm of soil and keep them moist. Sowings in spring and late summer work best; in high summer, choose a partly shaded spot. If you want to save seed, let a few plants flower; the yellow flowers are popular with bees. Because pak choi, mizuna, spring turnip greens, turnip tops and other relatives cross easily, the seed only stays true to type if none of them flower nearby.
Companion planting
Good neighbors
legume family (Fabaceae)
particularly well establishedLeguminous plants collect nitrogen in the soil, from which Brassicaceae benefit as heavy feeders.
For example PeaBush beanPole beanBroad beanSnow peaWrinkled pea and 36 more species in the catalogue
Source: classic companion planting (DACH-Gartenpraxis)
carrot family (Apiaceae)
You can pair celery and dill with all Brassicaceae because they repel the cabbage whitefly with their scent, a proven companion.
For example CarrotCeleriacDillParsleyFlorence fennelCoriander and 21 more species in the catalogue
Source: Bio-Gärtnerei Mixed-culture Practice
mint family (Lamiaceae)
You will notice that the intense scent of basil, thyme, and others confuses the cabbage whitefly and keeps it away from the cabbage family.
For example LavenderThymeBasilRosemarySageHyssop and 43 more species in the catalogue
Source: bio-gardening intercropping practice
nasturtium family (Tropaeolaceae)
Nasturtium serves as a trap plant for you. Aphids and cabbage whiteflies prefer it over the brassicaceae next to it.
For example NasturtiumMashua
Source: Trap plant practice in organic horticulture
Companion planting is partly traditional gardening lore. Where the reason is known, it is given.
Some of these explanations were machine-translated.
For your garden
Grow Komatsuna yourself
Gartenkern tells you when frost is coming, when to sow and when to harvest, for your location.
Free, no time limit
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