Echinops ritro – Blue Globe Thistle
Perennial. Zone 2. Asteraceae, formerly Compositae. East-Central Europe, Asia. The genus name is from the Greek echinos = “hedgehog-like” (in some references “sea-urchin-like”) – in reference to the spiky structure of the bloom; ritro = “of gardens”.
This is often the first Globe Thistle every gardener starts out with – my original plant is alive and well and giving great pleasure more than twenty years after I received a hefty division of it, overflowing its disintegrating cardboard box, from a fellow-gardener friend. I’d admired her gorgeous dried flower bouquets containing the perfectly round, frosted blue Globe Thistles at an early autumn farmers’ market, and she remembered my interest the following spring.
Though the common name “thistle” might cause the neophyte Echinops grower some initial concern, the prickles on this plant are soft and benign. The lush, dark green, raggedly-cut foliage is tipped with flexible points, but they do not detach, and the plant can be handled easily with bare hands.
Echinops ritro is a clump former, with a height of 2 to 4 feet or so, depending on soil fertility and moisture, and a spread of about half its height.
Echinops ritro – Blue Globe Thistle – flowering stage – note the bee. Image: Kristian Peters
Sturdy stems covered by fine white hairs produce perfectly globular buds in mid-summer, and these enlarge and expand and take on an increasingly intense blue tint, until the tiny electric-blue flowers pop open one by one and immediately attract bees, butterflies, and a host of other nectar and pollen seeking visitors. Bloom time of the large golf ball-sized and -shaped flower clusters is extended, easily 6 to 8 weeks or more, and the aging flower heads stay attractive well into fall, when they will be visited by chickadees and other small birds which relish the seeds.
Echinops ritro – aging seed head – still blue, and still showing its perfectly globular structure – Hill Farm – early October, 2013. Foliage in background is of Plume Poppy, Macleaya cordata. Image: HFN
Echinops ritro is hardy and drought tolerant, but produces the best show in good garden soil with summer moisture. It spreads modestly at the roots, expanding its clump year by year, and it will also self sow in a mild way. Plants are tap rooted, but mature clumps may be divided with care in early spring.
Full sun to light shade is acceptable to this plant. It combines beautifully with the other blue garden thistle, Eryngium planum (Blue Sea Holly), as well as fall-blooming sedums such as Hylotephium x ‘Autumn Joy’, any of the Rudbeckias, and all sorts of ornamental grasses.
