Scottish Thistle Cynara cardunculus

Native to the Mediterranean region, Cynara cardunculus grows as a perennial in locations that experience temperate climates, where the summers are cool and the winters mild. It was introduced to the US in the 1800's.  Can be found growing in disturbed open sites, such as grassland, chaparral, coastal scrub and riparian areas.  

It has prickly, deeply cut, gray-green foliage and tall flower stalks topped with brilliant purple flowers.  While it is a perennial, it is often grown as a half-hardy annual.  Annual plants may not have enough time to grow before flowering, but the large, jagged leaves provide ornamental interest all of their own.

The attractive foliage starts out silver, becoming a gray-green as they grow.  They can reach lengths of up to 3'.  As the leaves age, they can begin to lose their upright form.  To keep a neat appearance, trim off the older leaves.  

Cardoons need rich, well-drained but moist soil and full sun to grow.  They may go dormant in hot summers and will die back in winter.  Mulch heavily to aid in winter survivability.  Considered weedy in some areas.  Be mindful of the spines along the stem, although spineless cultivars exist.

The flowers can be cut or dried and, while edible, are not considered as suitable for eating as Scolymus Group artichokes.  Instead, the young, emerging leaf stalks are blanched, harvested, cooked, and eaten as a vegetable.

The above ground portion of the plant dies to the ground each year, but will regenerate itself from its large, deep taproot.  

Insects, Diseases, and Other Plant Problems:   Diseases that may damage this plant include root rot, gray mold and powdery mildew.  Insect problems include snails, slugs and aphids.  

In some locations, such as California, it has spread to form colonies, and is considered to be invasive.  The large taproot must be removed to avoid new sprouting.

Strong winds can damage this plant.

VIDEO created by Andy Pulte for “Landscape Plant Identification, Taxonomy and Morphology” a plant identification course offered by the Department of Plant Sciences, University of Tennessee.