Common Name: Sea Kale, Crambe, Scurvy Grass, Halmyrides
Scientific Name: Crambe maritima
Family: Brassicaceae (the Brassica, Crucifer, or Broccoli family)

Sea Kale in a clump forming, edible perennial.

Sea Kale in a clump forming, edible perennial.

Description:
Despite its name and its origins on the European Atlantic coasts, Sea Kale does not need a nearby ocean to thrive. This Brassica has edible roots, shoots (like asparagus), leaves (like kale, cabbage, or spinach), and flower heads (like broccoli), and it is perennial! It is drough tolerant and attracts beneficial insects with it numerous, fragrant flowers. It is time more people rediscover this amazing plant that belongs in our forest gardens and on our plates.

 Carmbe maritima Johann Georg Sturm, 1796, from Deutschlands Flora in Abbildungen

Crambe maritima Johann Georg Sturm, 1796, from Deutschlands Flora in Abbildungen

History:
Native and widespread on the Atlantic coasts of Europe, it was wild harvested likely for thousands of years before it was first cultivated in the 1600’s. It became a rather popular garden vegetable in the 1800’s in Europe and North America. But due to it does not store or ship well, there was not place for Sea Kale in “modern” agriculture. It has been gaining ground as an ornamental, and more people are rediscovering this perennial vegetable. It has also been naturalized (gone “wild”) on the West Coast of North America.

Trivia:

  • Thomas Jefferson raised Sea Kale and was listed in his Garden Book of 1809.
  • Sea Kale shoots can easily be blanched, and local Europeans routinely covered the emerging shoots with loose rock to do this.
  • Sea Kale was preserved and used by the Romans on long ocean journeys to prevent scurvy. It is naturally high in vitamin C.
    Sea Kale has edible leaves...

    Sea Kale has edible leaves…

    ...edible shoots (that can be blanched)...

    …and edible shoots (that can be blanched).

USING THIS PLANT

Primary Uses:

  • Edible Leaves – Raw or cooked. Can be used like Kale or Collard Greens. Young leaves are best for eating raw (kind of like spinach); they get very tough and bitter when older. They have a cabbage or kale-like flavor (hence the name!).
  • Edible Stems – Raw or cooked. Mainly the very young and thin stems. Can be cooked along with the leaves or trimmed and cooked on their own.
  • Edible Shoots – Naturally purple, but commonly blanched. Raw or cooked, but usually cooked like asparagus. Crisp with a fresh, nutty flavor and a hint of bitterness.
  • Edible Flowers and Flowering Stems (Heads) – Raw or cooked. Used like broccoli but with smaller florets… closer to a broccolini or broccoli raab (rapini), but with a good, broccoli-like flavor.
  • Edible Roots – eaten cooked (boiled, roasted) and are starchy and a little sweet.

Secondary Uses:

  • Ornamental Plant – this plant has become more popular in recent times as an ornamental, with its big leaves and abundant, fragrant flowers. It has gained the British Royal Horticultural Society’s Award of Garden Merit.
  • Maritime Plant – like most species in the Brassica family, Turkish Rocket can withstand maritime conditions; however, this plant is one of the few plants that are considered true halophytes… meaning they can grow in water with high salt content.
  • General insect nectar plant – especially bees and parasatoid wasps
  • Butterfly nectar plant
  • Drought Tolerant Plant – once established (due to the taproot)
  • Dynamic Accumulator – although I can find no good information to support this, it is likely considering its taproot. If it is like other Brassicas, then it would accumulate Phosphorus and Sulfur.
  • Groundcover Plant – this plant can be used as a groundcover, but probably would do best in a mixed species groundcover planting. Martin Crawford recommends planting Sea Kale with Chinese Bramble (Rubus tricolor), a groundcover raspberry. Plant Sea Kale every 2 feet (60 cm) for good coverage.
  • Animal Fodder Plant – like all Brassica’s one of its original uses. Cattle, sheep, swine, and poultry all can/have used this plant for food.

Yield: Variable, older plants have larger bulbs. Improved varieties also have larger bulbs.
Harvesting: Leaves are harvested in Spring when small and tender. Older leaves are tough (and get tougher when flowering), and can be eaten if cooked long enough, but they are often left on the plant to allow it to remain strong enough/build reserve to live through the dormancy of the cold months. Shoots are also harvested in Spring when small and tender (about 6-9 inches/15-22 cm); blanching makes them more mild in flavor, but decreases the nutrients. Flowering stems (heads) are harvested like broccoli in Summer. Roots are dug up when the plant is dormant. Typically only the smaller, outer roots are harvested, and the central, main taproot is left to continue growing.
Storage: Use within a day – Sea Kale does not store very well. Roots can be stored in damp sand for a few months before eating or replanting.

The flower heads are also edible... just like broccoli.

The flower heads are also edible… just like broccoli!

...and the roots, which can be quite large, are also edible.

…and the roots, which can be quite large, are also edible.
(that’s a key sitting on the root)

Another view of the taproot from a plant that had its soil eroded from under it.

Another view of the taproot from a plant that had its sandy soil eroded from under it.

DESIGNING WITH THIS PLANT

USDA Hardiness Zone: Zone 4-9
AHS Heat Zone: Zone 9-6
Chill Requirement: Likely considering where this plant originates, but no reliable information is available.

Plant Type: Herbaceous, mound-forming, spreading plant
Leaf Type: Deciduous
Forest Garden Use: Herbaceous Layer
Cultivars/Varieties: There are a few varieties available.

Pollination: Self-fertile. Pollinated by bees, flies, wind.
Flowering: Summer (June-August)

Life Span:

  • Years to Begin Harvesting: leaves and flowering stems (heads) can be harvesting in the first year, but shoots should not be harvested until at least year 3 (similar to asparagus).
  • Years of Useful Life: About 10-12 years. Considering that the plants can be propagated easily from division, an individual’s life span is likely irrelevant.
This is what Sea Kale will die back to each Winter.

This is what Sea Kale will die back to each Winter.
(you can see the purple shoots just starting to grow)

The classic Brassica pattern of growth.

The classic Brassica pattern of growth.

The fragrant and numerous flowers attract beneficial insects.

The fragrant and numerous flowers attract beneficial insects.

 

PHYSICAL CHARACTERISTICS OF THIS PLANT

Size: 2-3 feet (60-90 cm) tall and wide
Roots: Taproot. As this plant grows, new taproots form with new growing points – these are what can be divided to form new plants.
Growth Rate: Slow

Sea Kale is a clump forming perennial.

Sea Kale is a clump forming perennial.

While it is naturally found on the coast, it can thrive in a garden as well.

While it is naturally found on the coast, it can thrive in a garden as well.

GROWING CONDITIONS FOR THIS PLANT

Light: Prefers full sun
Shade: Tolerates light shade
Moisture: Prefers moist soils, but is drought tolerant once established.
pH: 6.5-7.5 (can tolerate anything but very acidic soils)

Special Considerations for Growing:
Sea Kale prefers moist soils. Other than that, it doesn’t appear to be too picky.

Propagation:
Easily from division (Spring or Autumn) or root cuttings (when dormant). Root cuttings are typically 1-4 inches/3-10 cm long and can be planted in place or in pots until they are growing well.  Also propagated via seed, but the seed does not store long.

Maintenance:
Minimal.

Concerns:
None.

 

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Photo References:

  • http://upload.wikimedia.org/wikipedia/commons/b/bc/Blanched_Crambe_Maritima.JPG
  • http://upload.wikimedia.org/wikipedia/commons/0/00/Crambe_maritima_flowers_062811.jpg
  • http://upload.wikimedia.org/wikipedia/commons/a/ab/Crambe_Maritima_Estonia.jpg
  • http://www.gallowaywildfoods.com/wp-content/uploads/2011/06/sea-kale-cloud.jpg
  • http://www.fosbeach.com/wp-content/uploads/2010/05/Sea-kale.jpg
  • http://upload.wikimedia.org/wikipedia/commons/d/d2/Sea-kale_(3676714910).jpg
  • http://mylittlecityfoodgarden.files.wordpress.com/2011/11/sea-kale-plant.jpg
  • http://sjhigbee.files.wordpress.com/2013/07/sea-kale-leaf-on-lton-beach1.jpg
  • http://mylittlecityfoodgarden.files.wordpress.com/2011/11/sea-kale-flower-bud.jpg
  • http://www.gallowaywildfoods.com/wp-content/uploads/2011/06/sea-kale-buds-e1341440257144-1024×575.jpg
  • http://seamagic.org/wp-content/uploads/2014/01/Sea-kale-roots-washed-up-on-Sizewell-beach-Dec-2013-Kate-Osborne.jpg
  • http://rxwildlife.org.uk/wp-content/uploads/2007/01/sea-kale-1.jpg
  • http://upload.wikimedia.org/wikipedia/commons/6/6d/Crambe_maritima_Sturm39.jpg