Brassica rapa subsp. oleifera
Winter turnip rape
Common names: Winter rape, Turnip rape, Winter rapeseed
At a glance
- Light
- Full sun
- Lifespan
- Annual
- Flowering
- Apr–May
- Hardiness
- Cold damage below −15 °C
- Water need
- Medium
Photo: Carl Axel Magnus Lindman · Public Domain · Source
This description was machine-translated.
Description
Winter turnip rape, botanically Brassica rapa subsp. oleifera, is an annual member of the cabbage family (Brassicaceae), sown in late summer. It overwinters as a leaf rosette, grows vigorously in spring, and reaches 60 to 100 cm in height. In April and May it bears bright yellow flowers that bees and bumblebees visit early in the year. In the garden, it covers cleared beds over winter, protecting them from nutrient leaching and soil crusting, holds nutrients that would otherwise reach the groundwater, and loosens deeper soil layers with its taproot. Unlike clover, it does not fix nitrogen; it only conserves what is already present in the soil. Because it belongs to the cabbage family, it needs attention in crop rotation: it should not be planted on beds affected by clubroot.
Care instructions
Sow winter turnip rape from mid-July to mid-September, broadcast or in rows, onto a cleared bed, and keep the soil evenly moist until emergence. In dry weeks, flea beetles can chew small holes in young leaves. Even moisture helps, and a few holes can be tolerated on a green manure area. In spring, cut the plants no later than full bloom in May, before seeds form. Let the cuttings wilt for a few days, work them in shallowly, and wait two to three weeks before sowing or planting. Crop rotation is important: winter turnip rape belongs to the Brassicaceae, like cabbage, radish, and daikon. Brassicas should return to the same bed only every three to four years. If clubroot is present in the garden, omit winter turnip rape entirely, as it promotes the pathogen.
The care notes were machine-translated from German.
Garden year
SowingJul–Sep
FloweringApr–May
Germination
- Soil temperature
- from 5 °C, ideally 18 °C
- Days to sprout
- 3 to 7 days
- Light
- Sprouts in light or dark
- Sowing depth
- 1.5 cm
- How to start
- Sow straight into the bed
Soil & site
Soil pH
Soil type
loamy, humus-rich, well-drained
Winter turnip rape grows in almost any garden soil, best in humus-rich, medium-heavy loam that holds water and is not compacted. Lighter soils work too, if they don't dry out completely in late summer. A pH between 5.5 and 7.5 suits it. It dislikes permanent wetness in winter, and you loosen compacted spots beforehand so that the taproot can go down.
Feeding
Medium feeder
Winter turnip rape needs no fertiliser. It takes up nutrients left in the soil after the harvest and holds on to them over winter instead of letting them wash into the groundwater. On very depleted beds you can work some ripe compost in shallowly before sowing. Extra nitrogen is unnecessary and only drives leaf growth.
Overwintering
Winter turnip rape is frost-hardy and overwinters as a leaf rosette in the bed, as a rule down to about minus 15 degrees. Bare frosts without snow cover and long wet spells affect it more than cold alone. In spring it shoots again from March and flowers in April and May. Mow it at the latest at full bloom, otherwise it self-seeds and turns up as a weed in the next crop. Let the cut material wilt for a few days and then work it in shallowly.
Propagation
Methods
- From seed
You propagate winter turnip rape only from seed, which you buy as green manure seed. Sow it directly on the cleared bed from mid-July to mid-September, best in August. Loosen the soil, broadcast the seeds, rake them in 1 to 2 cm deep and firm the surface. With moisture they come up after just a few days; in July, keep the soil evenly moist until then. Don't collect your own seed: if you let plants go to seed, the green manure turns up next year as a weed in the vegetable bed.
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 Winter turnip rape 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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