Trunkline Magazine (Louisville Zoo) September 2018 - Page 21

GARDEN TALK Autumn purples By Matt Lahm, Asst. Curator of Education The monarch migration is upon us! As September arrives, so does the flight of the monarch but- terflies. Did you know monarch butterflies love the color purple? It’s the color of some of their favorite flowers! As we prepare for this year’s Flutter Fest (read more on page 9) and the season ending of the Butterflies n’ Blooms exhibit, learn about two native wildflower species that would be excellent additions to add some spectacular purple hues to your gardens. Both of these plants are available from our Butterflies n’ Blooms partner, Idlewild Butterfly Farm. Our first species is called aromatic aster, Symphyotrichum oblongifolium, and is a native pe- rennial wildflower distributed over much of the eastern and central U.S. It grows 1 to 3 feet in height and width producing small, daisy- like flowers less than 1 inch in diam- eter with violet-blue rays and yellow centers. It prefers dry soils and full sun, but will grow in well-drained, moist soils and partial shade. It is a hardy plant that can tolerate cold, heat, poor soils, and drought once it is established. Aromatic aster creates showy mounds of blooms in fall and is excellent for native land- scape gardens. It can be planted and transplanted in the spring or fall and should be cut back after it goes dormant in late fall/early win- ter. There are no serious insect or disease problems that aromatic as- ter experiences, but it is susceptible to mildew and fungus which is typi- cally initiated by the plant remaining moist for an extended period. Ironweed, Verno- nia noveboracen- sis, is our second plant choice and, like the aromatic aster, it also belongs to the aster fam- ily. Ironweed is a native, herbaceous perennial typically found grow- ing in meadows, moist thickets, with average to wet soils and full sun. It can be seen throughout the eastern U.S. How- ever, this plant, like the aromatic aster, tolerates a wide range of soil conditions. Ironweed is another low maintenance plant that is best planted in the rear of a gar- den area, as it can reach heights of 6 to 7 feet and spread 3 to 4 feet at the crown. The plant height may be reduced by cutting back the stems in late spring. The most attractive feature of Ironweed is the cluster of brilliant purple flowers. Bloom time for Ironweed is late summer into early fall. The rusty color and the plant’s tough stem is the reason for the ironweed's name with dark rigid stems topped with contrasting fluffy seed heads, offering excellent late season color and texture. An excellent addition to the pollinator garden, the brilliant purple-crimson bloom color is very attractive to butterflies, and ironweed is a host plant for the American painted lady butterfly too! Top: Aromatic Aster Middle and bottom: Ironweed Louisville Zoo Trunkline • Fall 2018 • 21