Crambe maritima
Sea kale
Common names: Sea cabbage
At a glance
- Light
- Full sun
- Spacing
- 75 cm, rows 90 cm
- Lifespan
- Perennial
- Sowing
- Mar–Apr
- Harvest
- Apr–May
- Hardiness
- Hardy down to −15 °C
- Water need
- Low
- Origin
- Native to Germany
Photo: Siim at et.wikipedia · CC BY-SA 2.5 · Source
This description was machine-translated.
Description
Sea kale (Crambe maritima) is a hardy coastal vegetable that grows wild on European pebble beaches and can remain in the same spot in a garden for many years. Its blue‑green, slightly wavy foliage forms a decorative mound that also works well as a perennial ornamental plant. The real delicacy is the young, pale shoots harvested in spring: under a blanching pot they develop a bright, tender flavor with a subtle aroma between asparagus and cabbage.
Care instructions
Plant sea kale in a sunny, sheltered spot with well‑drained, sandy soil; if the soil is heavy, loosen it with sand or fine gravel beforehand. Space plants 75 to 90 cm apart to allow the robust roots and wide canopy to develop freely. In early spring (around week 10, early March), cover the emerging shoots with a light‑tight pot to blanch; after 4 to 6 weeks the shoots are ready for harvest and taste best. Water only during prolonged dry periods, as sea kale tolerates sandy, drier soils. In autumn, cut back dead foliage; a mulch layer of leaf or straw can protect the roots over winter but is usually not essential.
The care notes were machine-translated from German.
Garden year
SowingMar–Apr
HarvestApr–May
Germination
- Soil temperature
- from 5 °C, ideally 12 °C
- Days to sprout
- 21 to 60 days
- Light
- Needs darkness to sprout
- Sowing depth
- 1 cm
- How to start
- Start indoors, then plant out
Soil & site
Soil pH
Soil type
well-drained, sandy, lean, dry
Sea kale comes from shingle beaches and steep coasts and wants a deep, very well-drained soil without waterlogging. Sandy to gravelly, calcareous soil best matches its natural site. Heavy, compacted soils you loosen generously at the planting hole with sand or fine gravel.
As a brassica, sea kale counts among the cabbage family, but as a perennial it usually grows in the same place permanently anyway.
Feeding
Medium feeder
Months
Mar, Apr, Sep
In early spring sea kale appreciates a helping of ripe compost, worked in shallowly around the plant. After harvest in early summer you can top up once more in late summer with compost or well-rotted manure, so that the plant gathers strength for next year. Mulch of leaves or straw retains moisture and slowly supplies nutrients on the side.
Overwintering
As a coastal plant from northern Europe, sea kale is fully hardy and needs no special protection. The foliage dies back in autumn, and in spring the plant grows anew from the strong rootstock. A mulch layer additionally protects the roots from freeze-thaw cycles and at the same time suppresses weeds.
Propagation
Methods
- From seed
- Division
- Cuttings
You start sea kale from seed in early spring, although germination can take several weeks and benefits from cold periods. Established plants can be propagated in early spring by dividing the rootstock; each piece needs at least one bud. Alternatively, in winter you cut root cuttings from finger-thick side roots and plant them directly in the bed, where they reliably shoot.
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 Sea kale yourself
Gartenkern tells you when frost is coming, when to sow and when to harvest, for your location.
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