Giant sea holly is a short lived herbaceous perennial often considered a biennial, and is native to the Caucasus and Iran. The first year it produces a basal rosette of spineless heart-shaped gray-green leaves that is followed in the second year by a flowering stem up to six feet tall with spiny leaves. In summer the small blue gray flowers are carried in closely packed cone-shaped umbels three to four inches long and subtended by eight or nine rigid, toothed silvery bracts. This is large plant and a good choice for the back of the border in a place protected from wind. Although it is short lived it usually self seeds. The flower heads add both texture and form to arrangements and are especially beautiful with gray and pink plant material. They can also be preserved for use in winter bouquets.
Cutting: Needs no special treatment.
Conditioning: Give a long drink in cold water
Preserving: Although the flower heads dry to a tan color they tend to loose their bracts so preserving with a glycerin solution is preferable.
Cultivation:
Size
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- : 4-6’ H x 4’ W
Light
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- : Full sun for best color
Soil
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- : Lean to average, dry, well-drained
Hardiness:
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- Zones 4-8
Propagation:
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- Seed, division
Care
- : Cut stems to the ground after flowering (however, most plants will not return a third year.)