684 Artemisia X 'Powis Castle'Common Names: Powis Castle artemisia Family: Asteraceae (aster/daisy Family)
Powis Castle artemisia is an evergreen (actually "eversilver") perennial with woody stems. It also can be classified as a shrub or sub-shrub. Artemisia X 'Powis Castle' is believed to be the result of a cross between Artemisia arborescens and A. absinthium. This is a beautiful silver-gray plant that grows in a dense, billowing mound up to 2-3' (0.6-0.9 m) tall and 3 to 6 ft (0.9-1.8 m) in diameter. The leaves are finely dissected like filigreed silver lace-work. Powis Castle rarely flowers, but some plants may occasionally produce 6 in (15.2 cm) panicles of silver, yellow-tinged flower heads. This artemisia has a more compact habit and is less leggy and sprawling than others.
Artemisia X 'Powis Castle' was first introduced into the horticultural trade around 1972 by a Mr. J. Hancock of Powis Castle in Wales. It is not clear whether Mr. Hancock made the original cross or someone else did and gave him a cutting. Both of the presumed parent species are cultivated as ornamentals. A. absinthium grows wild in Europe and temperate Asia and has become naturalized in NE US. A. arborescens occurs naturally in the Mediterranean region. Powis Castle artemisia occurs only in cultivation.
CulturePowis Castle benefits from pruning to keep it in a compact mound. But don't prune in fall; prune when new growth starts in spring. Light: Full sun or partial shade. Moisture: Likes a very well drained soil, but with regular watering. Hardiness: USDA Zones 6 - 8. Powis Castle can't take the heat in warmer zones or the cold in cooler zones. Propagation: Powis Castle can only be propagated from cuttings. Start new cuttings regularly and keep several plants around because Powis Castle artemisia has a tendency to up and die rather unexpectedly.
Powis Castle is one of the hardiest and strongest and most beautiful of the silver-gray "Dusty Miller"-type wormwoods. It is more tolerant of summer heat and humidity than the others. Show off its lacy silvery foliage in mixed shrub and perennial borders. Use it to soften bright red and orange flowers and to blend with blues and lavenders. Powis Castle is at home in a rock garden, a herb garden, or as a stand-alone specimen.
When you see a genus name with an X and a single quoted phrase like: Artemisia X 'Powis Castle'. Say it out loud as: "artemisia, the hybrid species 'Powis Castle'".
Powis Castle is hardier and more heat tolerant than either of its parents and keeps its silvery gray foliage all year. The foliage is more sweet-smelling than other artemisias, too. Alan Armitage, horticulture professor at the University of Georgia and author of numerous technical and popular gardening books, says that Powis Castle is "one of the finest plants in cultivation." Quite a recommendation!
Artemisia absinthium, one of the presumed parents of Powis Castle, is the plant from which absinthe, a mind-altering alcoholic beverage is prepared that was famously used by 19th century European artists and whose use is now enjoying a renaissance.
Steve Christman 1/12/00; updated 10/18/03, 5/25/09, 6/9/10