Globethistle

Blue Glow is an upright globe thistle with silvery-green, prickly leaves and intense blue spherical flower heads held above the foliage in summer. Its mature size varies among references, so allow roughly 2–5 feet of height and 1–3 feet of spread; [the RHS and Lurie Garden provide cultivar-specific descriptions and dimensions](https://www.rhs.org.uk/plants/350990/echinops-bannaticus-blue-glow/details). ## Placement and season Give this perennial full sun or partial shade and well-drained soil. It suits a sunny border, gravel garden, wildlife planting, or cutting bed, where the round blue flowers add strong vertical shape. Published hardiness is USDA zones 3–8. The clump is long-lived and takes a few years to reach its mature size, so leave space around it for the spiny leaves and tall stems. ## Flower and seed care The flowers are useful fresh or dried. Deadhead spent heads if you want to limit self-seeding; leave a few standing when you prefer a natural look and winter structure. Water new plants through establishment, then irrigate as needed for the site rather than keeping the soil constantly wet. Good drainage matters even in soils that retain some moisture. ## Maintenance