Compared to the dull green of common tansy, 'Isla Gold' is brilliant. Where common tansy recedes, 'Isla Gold' takes center stage. A showy plant isn't necessarily big news. But this one brings along with it all the gutsy vigor and adaptability of its distant ancestors--meaning it's one of the toughest and most resilient perennials you'll find.
Its common name suggests just how tough. The word tansy has worked its way to us from middle English, via middle French, from the Greek athanatos meaning immortality. While tansy is a strong-smelling herb and does have a history of medicinal uses, I suspect it was the plant itself that was judged immortal.
Tansy came from Europe to North America probably with early settlers, long enough ago that it now behaves as a native plant here, growing along roadsides and fences throughout New England, west to Minnesota, and south to Missouri. Use 'Isla Gold' tansy to add a spot of color that lasts from early spring until frost knocks it down.
Tansy, sometimes known as golden buttons, is Tanacetum vulgare, and this new golden-leaved form is 'Isla Gold'. The highly aromatic lacy or fernlike, 2- to 6-inch-long chartreuse leaves grow along main stems that can reach 4 feet tall, but usually top out around 2 to 3 feet. The plant grows in a gradually expanding clump, so you can control its width. Petalless, buttonlike flowers that are 3/8 to 1/2 inch in diameter cover the plant in late summer into fall with large, flat-topped clusters.
'Isla Gold' is hardy to -30 oF, or USDA Zone 4. It will grow well throughout the dry West, even in zones 9 and 10, but does languish in the heat and humidity of southern zones 8 through 10. Grow in full sun in ordinary to dry soil. Cut back in July to refresh leaves if you don't care about the flowers. Use a spade to cut through and divide the clump in either spring or fall to both propagate it (or share with friends), or to restrain its spread.
Although tansy is no longer used medicinally, it also offers a long history of being a useful repellent of flies and ants. At the same time, some gardeners report it is also a powerful attractant of ladybugs.
Michael MacCaskey was editorial director at National Gardening.
Photography by Springhill