Zone:  Not fully hardy here (Zone 6a) so treat as an annual.  Our starts are "vernalized" (subject to a cold period so that they will behave as a biennial and produce artichokes).
Height:  0.5-1.5 meters (1.5-5 feet)
Spread:  1.0-1.2 meters (3-4 feet)
Bloom:  Most of our starts will set multiple buds (see Zone, above), which are the edible artichokes.  These generally are produced from August until frost.
Flower:  If the artichokes are not harvested, these buds will bloom with a spectacular purple thistle.
Foliage:  Velvety silvery-blue-green giant leaves, deeply cut
Light:  Full sun
Water:  Minimal, once established; mulch helps keep plants happy
Soil:  Rich and well-drained 
Other:  Artichoke buds should be harvested when very young (most of young but is edible), or when full and round (edible heart), and before they begin to develop their flower (no longer edible).
Garden locations:  A dramatic and bold ornamental as well as a specialty food plant.  As a thistle, the plants are prickly and best not planted where you casually walk.