Powis Castle artemisia is grown for its finely cut, silver-gray foliage, which billows into a soft mound 2 to 3 feet tall and noticeably wider. It rarely flowers, so the silver stays clean all season, cooling down hot color schemes and setting off purples and pinks.

Full sun and sharp drainage are the whole recipe; it laughs at drought, heat, deer, and rabbits once settled. Avoid rich, wet soil and keep mulch off the crown. Shear it lightly in spring to keep the mound dense; in mild winters here it holds much of its foliage.