Winter is the garden’s quiet time when its subtler charms hold sway. It’s the season of the three B’s – eye-catching bark, colorful berries, and architectural branching – and of evergreen foliage. And it’s also the time to appreciate the marvelous and often beautiful diversity of seed heads.
No plants better exemplify this beauty than grasses. Many produce large, elaborate flower heads that reach their full glory in fall and winter as the seeds ripen and scatter. Doubtless, the best known of the bunch (at least in eastern North American gardens) is Chinese maiden grass, Miscanthus sinensis. This variable East Asian native produces huge, plumy, silvery flower heads in late summer on 5- to 8-foot talks that erupt from fountain-like clumps of arching leaves. The ripening blooms gleam in the slanting fall and winter light, glowing most brightly when backlit by the sun.
Among the many outstanding varieties of Chinese maiden grass are the longtime favorite ‘Gracillimus’ and its descendants, all of which feature narrow leaves with silvery midribs. Broad, yellow, widely spaced bands mark the leaves of ‘Zebrinus’, which is floppier in habit than the similar ‘Strictus’. The broad-bladed, variegated Miscanthus sinensis var. condensatus ‘Cabaret’, has cream-striped leaves and reddish plumes that dry to silvery tan in fall. Compact cultivars such as the 40-inch-tall ‘Adagio’ make a good choice for tighter spaces. This (and other) grass species may self-sow, particularly in warmer parts of its USDA Zones 5 to 9 hardiness range.
Other notable grasses of winter interest (and of similar hardiness range) include:
The North American native Panicum virgatum (commonly known as switch grass), which produces hazy clouds of dainty pale flowers that darken as they ripen in fall. Most varieties grow to 4 feet or more.
Fountain grass (Pennisetum alopecuroides), instantly recognizable by its large foxtail-like flower heads on 3-to 4-foot stems above finely textured mounds of narrow leaves. Several dwarf cultivars (including ‘Little Bunny’) are available.
The upright, tassel-flowered Calamagrostis acutiflorus (feather reed grass), with bronzy blooms that mature to beige tones as they mature in late summer and fall.
Cortaderia selloana (pampas grass) is an imposing tender grass surviving in USDA hardiness zones 8-10. The tall plumes reach 8-12 feet and appear late in the season. It can seed freely, so be cautious where you plant it.
These and most other ornamental grasses flourish in relatively fertile, not overly dry soil and full sun. A good nitrogen-rich soil amendment (such as Fafard Garden Manure Blend) will help bring heavy or sandy soils up to snuff.
Like grasses, many broadleaf perennials have attractive seed heads that make a pleasing sight in winter (particularly when displayed against a blanket of snow). Among the best perennials for winter interest are species in the aster family that bear persistent conical heads of dark seeds. The near-black central cones of perennial garden favorite Rudbeckia fulgida remain long after the last golden-yellow petals of its summer-to-fall ray-flowers have dropped. Usually sold under the name ‘Goldsturm’, it’s one of a tribe of similar ‘black-eyed Susans” from the central and eastern United States. All are easy-care sun-lovers, are hardy from zones 4 to 10, and have a penchant for self-sowing. Rudbeckia nitida, by contrast, has greenish cones (with yellow petals) on stately, 4- to 6-foot stems, and is a less enthusiastic self-sower.
Also hailing from prairies and meadows of central and eastern North America are several species of purple coneflower (Echinacea purpurea and others). The large brown “cones” protrude pleasingly from the snow on 2- to 4-foot stems and also look nice in summer when fringed with purple-pink ray-flowers. Hybrids and selections of purple coneflower come in a host of flower colors, from white to red to yellow.
The North American prairies are home to several other perennials that make great winter garden ornaments. The silver-white, spherical flower heads of rattlesnake master (Eryngium yuccifolium) ripen into spiky globes that resemble some sort of miniature medieval weaponry. They cluster atop 3-foot stems that arise from rosettes of fleshy, spiny, yucca-like leaves. False indigo (Baptisia australis) and its kin are big bushy legumes that produce blue, white, or yellow pea-flowers in late spring and early summer, followed by peapods that become leathery and brown-black as the seeds mature in fall. All make wonderful low-maintenance perennials with spring-to-winter interest.
Attractive seedpods are also a feature of the many butterfly weeds (Asclepias spp.) that dot the prairies and fields of eastern and central North America. The pods split in fall to release seeds that float away on tufts of white down. Orange-flowered Asclepias tuberosa is one of the best, as is Asclepias purpurascens, which has rose to purple blooms. Tall Sedums (Sedum spp.) of all types also grace the winter with seedheads that can remain attractive through winter.
Sweet autumn clematis (Clematis terniflora) is one of the numerous Clematis species (including many shrubby and vining perennials native to central and eastern North America) that bear seeds with plumy, silver-white appendages that continue to draw onlookers long after their flowers have fallen. Heavy-blooming plants appear to be enveloped with a feathery froth as the seeds (and their plumes) mature. As with all of the above (as well as the scores of other perennials, shrubs, vines, and trees with ornamental seeds), they’re essential elements of the winter garden and splendid accents for fall and winter flower arrangements.