Sea Kale

Crambe

Crambe cordifolia ( Giant Heartleaf Sea Kale )
A fast growing to invasive, very long-lived, massive perennial, reaching a maximum size of 10 x 7 ( rarely over 8 x 6 ) feet.
The huge, toothed, deeply-lobed, heart-shaped, cabbage-like leaves, up to 3 ( usually 1.5 ) feet across, are mid-green. The foliage forms a large mound.
The very small, white flowers are borne on airy open panicles, up to 4 feet across, during early to mid summer.
Hardy zones 3 to 8 in full sun on consistently moist, deep, rich, well drained soil. Clumps can be divided during early spring. It is not prone to insect pests or disease.

Crambe maritima ( Sea Kale )
A vigorous perennial, reaching a maximum size of 3.3 x 4 feet; that is native to Europe from the British Isles to the Black Sea.
The thick, fleshy, cabbage-like leaves, up to 24 x 24 inches, are glossy silvery-blue to blue-green.
It is edible, the shoots can be served steamed like Asparagus with melted butter, salt and pepper.
The profuse, white flowers are borne on sprays, up to 2 feet in length, during early to mid summer.
Hardy zones 4 to 8 in full sun to partial shade on sandy, very well drained soil. The strong deep root system hates transplanting.

* photos taken on Aug 1 2013 in Stratford, Ontario

* video found on Youtube