Originally published in the Ithaca Journal, August 2002
By Mary Hirshfeld, Horticultural Curator at Cornell Plantations
With Labor Day past, the end of summer seems nearby and the gardening season nearly at an end. Yet there are a number of lovely herbaceous perennials that are just getting started as the traditional gardening season draws to a close.Kirengeshoma palmata, a woodland plant native to Japan, produces a profusion of nodding yellow bell-shaped flowers with delicately arched petals, starting at the end of August and continuing well into September. At Cornell Plantations, a mass planting of Kirengeshoma, located on the slope above the chipped pathway on the west side of Comstock Knoll, always elicits admiration. The pendulous flowers weigh the stems down slightly, so they are best seen from the path below. Although for most of the gardening season, Kirengeshoma has only its leaves to offer, they are large, bold leaves. So, the bushy 3- to 4-foot-tall plants manage to establish quite a presence in the garden, even without their flowers. A plant that doesn't appear at all until early fall is the diminutive Cyclamen hederifolium, a hardy miniature version of the cyclamen sold by florists. Native to southwestern Europe into the Mediterranean region, Cyclamen hederifolium, like its flower store relative, is a tuberous plant. This means that it has an underground stem that stores carbohydrates and requires a dry dormant period, similar to crocuses or other bulbous plants. The leafless flower stalks literally pop out of the ground in September, each topped by a delicate pink or white flower that looks like an inverted bishop's cap. The flowers are quickly Dwarf Cyclamen followed by the unfurling of beautifully marbled silver and green leaves. The flowers bloom even through several hard frosts, and the evergreen leaves stay attractive throughout the winter--although in our climate they are often buried beneath the snow. By early summer the leaves begin to yellow and die down as the plants enter their summer dormancy. Cyclamen hederifolium is a lovely and very long-lived perennial that is well worth finding a partially shaded spot for in your garden. Look for these plants in the shaded part of the Groundcover Collection, which surrounds Plantations' Headquarters Building. A plant on a scale to match the tiny hardy cyclamen is the late-blooming hosta (Hosta tardiflora). Only 8 to 10" in height when in full flower, this diminutive green-leaved hosta is often overlooked in favor of the larger, more boldly-colored hybrids. At home in a shaded rock garden or along the edge of a shaded perennial garden, Hosta tardiflora carries crisply attractive dark green leaves throughout the summer. In September, it lifts spires of small, surprisingly showy lavender flowers above its clumps of basal foliage.
At the opposite end of the size spectrum is Eupatorium purpureum 'Gateway', a very tall selection of our native Joe-Pye Weed. Although blooms begin to open in mid-August, flowering continues through September. In combination with ornamental grasses, this Joe-Pye makes a stunning late season display. Like many native American plants that are familiar roadside companions, Eupatorium purpureum originally found a place as an ornamental in European gardens. German plant breeder Ernst Pagels spent many years selecting the largest-flowered individuals from groups of seedlings, crossing those, and then once again selecting those with the largest flowers, until after many generations, he was satisfied with the six- to eight-foot-tall 'Gateway' and its gorgeous dinner-plate-sized flower heads. 'Gateway' has since made its way back to America, where it has become a staple of fall gardens throughout the Northeast. It combines well with the yellow striped zebra grass (Miscanthus sinensis 'Zebrineus') or with white vertically striped variegated grasses such as Miscanthus sinensis 'Rogolette'. Look for 'Gateway' in Plantation's Peony Garden--you can hardly miss it!
The tall sedums provide an indispensable group of plants for late season interest. Now grouped by taxonomists under the name Hylotelephium, Sedum is still the name used in the American nursery trade. Most of those offered are Sedum spectabile or Sedum telephium. 'Autumn Joy' is probably the most widely planted and best known. Its strong bushy habit and light green leaves are attractive throughout the summer, providing a nice textural contrast to vertical growers such as Siberian iris, or more delicately textured plants such as baby's breath. In the fall, each stem is topped by a plate-shaped flower head of rich pink that ages to mahogany-red and remains interesting well after the snow flies. Lately, a few darker-flowered selections have been introduced as well. One is 'Green Expectations', whose dark pink flowers are accompanied by purplish foliage. Another is 'Munstead Red', and a third is the more vividly pink flowered 'Neon'. A favorite of mine is 'Morchen', an 18" sedum which sports dusky pink flowers, and powdery grey foliage, often tinged with plum. The taller fall-blooming sedums are excellent, trouble-free, very long-lived perennials, whose looks benefit if the plants are divided every three or four years.The Japanese garden anemone (Anemone xhybrida) is a valuable addition to any fall garden. Flowers range from white through various shades of pink, and can be single, semi- or fully-double. Often thought to be marginally winter hardy in our area, anemones can be successfully grown here; just be sure to transplant or divide them in spring rather than fall, and to plant them in a well-drained site. While they are adaptable to partial shade, Japanese anemone's 3- to 4-foot-tall flowering stems may become floppy and require staking if they are not planted in full sun. Several selections have been reliable performers. Anemone Hubensis (white) and Anemone Vitaflora (pink) here at Plantations: 'Honorine Joubert', which has a hefty single white bloom with a lovely central tuft of golden stamens; 'Max Vogel', a vigorous grower with single soft pink flowers; and for smaller spaces, the 18 to 24" tall 'Prince Henry', with its rich purple-pink semi-double to double flowers. You'll find Japanese garden anemones throughout Plantations' gardens when you visit this fall.