Buy Asphodeline lutea [blue-leaved form]

One of the best of the old fashioned garden standards for the modern landscape. Herbaceous perennial native to the eastern Mediterranean. Narrow blue-green leaves form clumps to 12" tall and long-lasting, highly scented yellow flowers rise above on leafy stalks in early summer. Full sun in well-drained soil with occasional summer moisture where dry, especially in the hottest climates. Frost hardy to -20F, USDA zone 6, and even upper zone 5 in protected locations with winter mulch.