With fall upon us, our new landscape designer, Amy Borsay, provides her top plant picks for fall interest. All are suitable for full sun and clay soils; as well as native plant, pollinator, and rain gardens; and pair well together in the landscape for a beautiful fall color display.
Pink Muhly Grass (Muhlenbergia capillaris) Pink Muhly Grass is one of our native ornamental grasses, growing 3-4’ tall and wide. It is a clump-forming grass with narrow, arching leaves. Pink, airy seedheads appear above the foliage in the fall, which makes muhly grass a striking plant when planted en masse or in combination with fall-blooming perennials. The seedheads fade to tan as winter approaches, providing winter interest in the garden. While pink muhly grass is an excellent rain garden plant, it does not like wet feet, especially during the winter.
Switchgrass (Panicum virgatum) Switchgrass is another of our native ornamental grasses. In contrast to muhly grass, Switchgrass has a narrow, upright habit, with several cultivars available in varying heights ranging from 2-8’ tall and slightly narrower, making it suitable for both small and large garden areas. The foliage generally tends to have a blue-green cast, which fades to attractive shades of red and tan in the fall. Similar to muhly grass, Switchgrass displays airy seedheads above the foliage in the fall, is spectacular planted en masse and with fall blooming perennials, and provides great winter interest in the landscape.
American Beautyberry (Callicarpa americana) American beautyberry is a native, deciduous shrub that grows up to 3-6’ tall and wide. Large, light to medium green leaves appear in the spring on long, arching stems, with small clusters of flowers appearing spring to mid-summer. While the flowers are insignificant, they mature into show-stopping bright purple berries in the fall, providing excellent winter interest – if not eaten by birds and small mammals first. American beautyberry blooms on new wood, so it is best pruned in early spring; focus on removing old canes and ensuring good structure. Excellent planted as a specimen or in a large grouping.
Hardy Hibiscus (Hibiscus spp.) Many people are familiar with the annual tropical hibiscus plants that are available in most garden centers. However, there are several native hibiscus species that are considered herbaceous perennials in our area, such as Hibiscus moscheutos and H. coccineus, commonly known as Swamp Rose Mallow and Scarlet Rose Mallow, respectively. Many cultivars and hybrids are available, with large, oftentimes dinner plate-sized blooms in various shades of white, pink, and red. These plants grow quite large, 4-8’ tall and wide, so give them plenty of room to grow. The flowers mature into beautiful brown seed pods that provide excellent winter interest in the garden. Hardy hibiscus should be cut back 3-4 inches to the ground in late fall. During the growing season, it can be pinched back to encourage bushier growth. Be aware that it is late to begin new growth in the spring, and can be a favorite of Japanese beetles.
Joe-pye Weed (Eutrochium spp.) Joe-pye Weed is an excellent back of the border plant in the perennial garden. Clusters of dusty pink flowers appear in mid-summer to fall on tall, upright stems. The flowers mature to attractive, fuzzy seedheads that are spread by the wind. Joe-pye Weed can grow quite large, up to 8’ tall or more depending on the species, although there are smaller growing cultivars available such as ‘Little Joe’ and ‘Baby Joe’. Still, give this plant room to grow. Joe-pye Weed does best in moist areas, but is adaptable to a wide variety of soils.
Swamp Sunflower (Helianthus angustifolius) Swamp sunflower is another excellent back of the border plant for the native/pollinator/rain garden, with a stunning display of bright yellow flowers in mid to late fall. It grows 6-8’ tall, with smaller growing cultivars available. The stems tend to be flimsy, so plant Swamp Sunflower next to other plants that can provide support such as Joe-pye Weed. Otherwise, staking may be needed. Prune back in early summer to encourage stronger stems and bushier growth. Swamp Sunflower is also a much better-behaved perennial in the garden than other Helianthus spp., slowly spreading by clumps.
Asters (Symphyotrichum spp.) There are several species and cultivars of Aster suitable for planting in our area. They tend to be upright and bushy, with heights ranging from 1-6’. The taller varieties can be kept shorter and bushier by pinching back the stems in late June. Perennial asters provide a gorgeous late season bloom display in the landscape, and are available in various shades of white, pink, purple, and blue; a great alternative to the annual florist chrysanthemums. The most important consideration for our area is choosing species and cultivars that have resistance to mildew and rust. Also keep in mind that some species are more aggressive and/or more drought tolerant in the garden than others.
Goldenrod (Solidago spp.) Not to be confused with ragweed, Goldenrod produces bright yellow clusters of flowers on tall, erect stems. There are several species and cultivars available. One of the most popular cultivars available is “Fireworks”, and true to its name, Fireworks explodes with color in the late season garden. Typical size of goldenrod is 2-3’ tall or more, though smaller cultivars such as “Little Lemon” are available. Goldenrod is easy to grow and is adaptable to a wide variety of soils. However, it does have an aggressive growth habit and may need to be divided every couple of years to control its spread.
Blazing Star (Liatris spicata) Beginning mid-summer, Blazing Star produces striking spikey flowers on upright stems with strappy, grass-like foliage. Depending on the cultivar, bloom color varies from pink to purple to white. The flowers mature into fluffy, attractive seedheads in the fall. Blazing Star is more adaptable to moist soils than other Liatris spp., but still requires good drainage. Height can vary from 2-6’, depending on cultivar. Taller varieties may need staking, or grown among other plants that can provide support.
Mountain Mint (Pycnanthemum spp.) As the name suggests, Mountain Mint is a member of the mint family, with foliage that emits a strong, minty fragrance when crushed. Several species are native to NC, with white blooming flowers that appear mid-summer to fall. Height ranges from 1-3’, and the plants are adaptable to a wide range of soils. Mountain Mint is a must for the native plant and pollinator garden, as it attracts a wide variety of pollinators and beneficial insects. Like Goldenrod, it can spread aggressively via rhizomes, and will need to be divided periodically to control its spread.
