Common Name: wormwood
Type: Herbaceous perennial
Family: Asteraceae
Zone: 6 to 9
Height: 2.00 to 3.00 feet
Spread: 1.00 to 2.00 feet
Bloom Time: August to October
Bloom Description: Yellow
Sun: Full sun
Water: Dry to medium
Maintenance: Medium
Flower: Insignificant, Good Dried
Leaf: Colorful, Fragrant
Tolerate: Rabbit, Deer, Drought, Dry Soil
Culture
Best grown in poor to moderately fertile, dry to medium moisture, well-drained soils in full sun. Excellent soil drainage is essential for growing this plant well. Does poorly in moist to wet soils where plants are susceptible to root rot. General foliage decline may occur in hot and humid summer climates.
Noteworthy Characteristics
Artemisia is a genus containing about 200 species of evergreen and deciduous shrubs, perennials and annuals mostly native to dry temperate regions of the Northern Hemisphere. Many of the species feature aromatic, pinnately divided or finely dissected silvery-green foliage and non-showy flowers.
Genus is named for Artemis, Greek goddess of the moon, wild animals and hunting.
‘Powis Castle’ is most likely a hybrid between Artemisia arborescens (large wormwood) and Artemisia absinthium (absinthe wormwood). It is a bushy, woody-based perennial or subshrub that is primarily grown for its aromatic, finely-divided, silvery, fern-like foliage which is feathery in appearance. It typically grows in a shrubby mound to 2-3’ tall and as wide, but spreads by rhizomes and may reach 3-6’ wide if not restrained. Tiny yellow-tinged silver flowers rarely bloom. Plants are essentially evergreen in warm winter climates.
‘Powis Castle’ was introduced in 1972 from the National Trust’s Powis Castle in Wales. Allan M. Armitage considers ‘Powis Castle’ to be “one of the finest plants in cultivation.” 1993 RHS Award of Garden Merit.
Problems
Plants tend to open up in summer. Susceptible to root rot in moist soils, particularly poorly drained ones. Watch for rhizomatous spread.
Uses
Ground cover plant for rock gardens, retaining walls, border fronts, between stepping stones.