Globe thistles are stalwart perennials that produce metallic-blue blossoms with perfectly round flower heads atop ribbed stems. Plants grow two to five feet tall and almost as wide. The spiny-edged leaves are white and woolly underneath.
How to grow: Globe thistles require full sun for strong growth but are not fussy about soil. Once established, they are very drought-resistant. Protect plants from aphids, and stake them if necessary.
Propagation: By division in the spring or by seed.
Uses: The larger species are impressive when used in background plantings or when grown as specimen plants. The smaller types are attractive in a bed, border, or wild garden.
Related species: Echinops sphaerocephalus is a species that is much taller, sometimes reaching seven feet, and is best used where a strong statement is needed.
Related varieties: Taplow Blue has intense blue color in the flowers and, at only two to three feet tall, is well behaved in borders.
Scientific name: Echinops ritro