The plants that come back. Herbaceous perennials rise from the crown each spring, flower through the warm months, and retreat to the ground in winter, returning larger the year after. They are the flowering heart of the border, the long-term investment that repays a gardener season after season.
Threadleaf bluestar is grown for two seasons at once: a haze of soft, powder-blue stars in late spring, and a billow of fine, needle-thin foliage that turns a blazing clear gold in fall. Native to the Ouachita Mountains of central Arkansas, Amsonia hubrichtii forms a large, dense, shrub-like clump of upright stems clothed in those threadlike leaves, and the autumn color alone earns a place in any sunny border.
The white-flowered form of swamp milkweed, Asclepias incarnata 'Ice Ballet' carries the same upright, well-mannered habit as the species but trades rosy pink for clusters of pure, cool white, held atop sturdy three-to-four-foot stems through summer. The effect is fresh and luminous in a moist border, and just as useful to wildlife.
A compact cast iron plant from Vietnam, Aspidistra vietnamensis 'Amanogawa' carries narrow, deep green, upright blades scattered with small creamy white spots, as if dusted with stars. The cultivar name, Japanese for the Milky Way, fits the effect exactly, and the speckled foliage brings light and pattern to a shaded bed where plain green would simply recede.
Canna flaccida is the wild golden canna of the Southern coastal plain, a native perennial with the broad, light green, tropical-looking leaves of the genus and large soft yellow flowers held above them in summer. Where the heavy garden cannas read as bedding, this species keeps a looser, wilder grace, the petals thin and almost orchid-like, opening in the morning and lasting a day.
This very rare aster, now placed in the genus Eurybia, is a true Florida endemic, native only to the moist pine flatwoods of the lower Apalachicola River. The plant is a botanical oddity: the clumping, foot-tall foliage is narrow, stiff, and grass-like, so unlike the leafy stems of an ordinary aster that a passerby might take the clump for a tuft of sedge. From late spring into early summer, slender flower stems rise above the leaves carrying clusters of inch-wide lavender-purple daisies, each ringing a small yellow eye.
Cuban rose mallow is one of the tall, slender members of the perennial hibiscus tribe, a plant that reads as airy and upright rather than bushy. Through the summer the stems carry fairly large flowers in a soft purplish pink, the classic mallow saucer set against distinctly gray-green foliage, and the stems themselves are lightly prickly to the touch. Rising to seven or ten feet on narrow clumps, the plant lifts the bloom well up where the color can be seen from a distance.
Hibiscus moscheutos, the rose mallow, is the hardiest of the perennial hibiscus and the tough, cold-proof parent behind most of the dinner-plate hibiscus sold today. The wild plant is a stout, clump-forming perennial of eastern marshes, rising to six or eight feet each summer and opening broad flowers to six inches and more, clean white or soft pink with a dramatic crimson eye at the center. For sheer size of bloom on a plant that shrugs off hard winters, little else compares.
There is a small lie in the name. Sanguinea means blood, and yet the iris in front of you is blue, or blue running toward violet, with only a wine-dark deepening in the falls to argue the case. The botanists felt the strain too: Carl Thunberg first tried to file the plant as Iris orientalis in 1794, found that name already taken, and the species waited until 1813 for the one carried since. The Japanese never bothered with Latin. To them the flower is ayame, one of the three irises of early summer, threaded through a thousand years of poetry and arriving in that uncertain seam where the old poets could never quite agree whether spring had ended or summer begun.
By late summer, when many shrubs have said their piece, Lespedeza thunbergii 'Spring Grove' is only clearing its throat. The many woody, arching stems bend into a green fountain through the season, then bow lower still under a long, generous fall of rose-purple pea flowers carried in racemes six to eight inches long. 'Spring Grove' is a newer selection said to hold darker purple flowers and a tidier, better habit than the old standard 'Gibraltar', and the photographs here come courtesy of the JC Raulston Arboretum.
Penstemon digitalis is one of the most adaptable of the native beardtongues, a clump-forming perennial of moist meadows, prairies, and open woods across the eastern and central United States. 'Husker Red', selected at the University of Nebraska and named Perennial Plant of the Year in 1996, keeps all the toughness of the wild species but wears it in deep wine-red: a basal rosette of glossy maroon foliage that holds color from spring through fall.
Physostegia correllii, Correll's obedient plant, is a rare and handsome member of the mint family, a robust, upright, somewhat succulent perennial rising from thick, spreading rhizomes. Among the false dragonheads the species stands out for unusually dark, glossy green leaves and cool purplish-pink flowers streaked and spotted with darker purple, an inch long and packed into dense terminal spikes.
Piloblephis rigida, wild or Florida pennyroyal, is a compact evergreen native mint from the sandy scrublands and pine flatwoods of Florida. The plant forms a low, tidy mound of fine, needle-like foliage that carries a clean, resinous, minty fragrance, released at a brush of the hand or on a warm afternoon in the sun.
Hardiness
Zones 8–10
Light
Full Sun
Height
1–2 ft.
Spread
2–3 ft.
Bloom
Purple
Plant type
Shrub
Traditional use
respiratory support, topical applications, general wellness
If any native perennial could be said to hum, the honor would go to Pycnanthemum muticum. From mid to late summer the blunt mountain mint gathers a shimmer of broad, silver-frosted bracts at the top of every stem, and within them open dense heads of tiny pink-to-white flowers that draw an almost comic density of life: bees of every kind, wasps, butterflies, skippers, moths, and flies working the nectar from dawn to dusk. In a three-year Penn State study that monitored eighty-six species, no plant drew a greater number and diversity of pollinators.
Rudbeckia fulgida var. fulgida is the true orange coneflower, the wild species that stands behind the famous 'Goldsturm', quieter, finer, and later to bloom than that celebrated garden child. From a low clump of dark, roughly hairy leaves rise branching stems two to three feet tall, each ending in a small golden daisy about two inches across, the deep yellow rays set around a low dome of brown-black. Where many of the black-eyed Susans have blazed and faded by August, the orange coneflower is only getting started, carrying many small flowers from late summer well into October.
Ruellia coccinea belongs to the acanthus family and comes from the Caribbean, native to Puerto Rico and the Virgin Islands, where the plant grows as a scarlet-flowered subshrub in warm, humid woodland. The Spanish common name, Yerba Maravilla, reads roughly as marvel herb, a fitting nod to the near-constant show. Through the whole of summer R. coccinea produces slender tubular flowers about an inch long, each opening into five spreading scarlet lobes, borne in clusters from the upper leaf axils and unfurling in succession from early summer until the first frost.
Salvia 'Indigo Spires' is a big, free-flowering hybrid sage grown for the long, tapering wands of violet-blue bloom it throws from early summer straight through to frost. Each spike packs small, rich violet flowers tightly in whorls above dark, near-black calyces, and the spikes lengthen and curve as the season goes, so a settled clump reads as a haze of deep blue-purple for months on end. Few perennials give so much color for so long a run.
Salvia leucantha, the Mexican bush sage, is one of the great fall salvias, grown for arching wands of flower that seem spun from felt. Long spikes rise above the foliage in late summer and fall, densely packed with velvety purple calyces from which small white corollas emerge, a soft two-tone effect that catches low autumn light and holds for weeks. Few plants close the gardening year with such generous, easy color.
Symphyotrichum oblongifolium, the aromatic aster, saves the best of the season for last. Long after most perennials have folded, this tough native throws up a low, spreading mound of stiff, well-branched stems and buries the whole clump under small violet-blue daisies, each lit with a bright gold eye, from early fall well into November. The show arrives just as the garden goes quiet, and the flowers hum with the last bees and butterflies of the year.
Most bluestars are smooth, cool customers; Amsonia ludoviciana is the outlier of the group. The Louisiana bluestar belongs to the dogbane family, Apocynaceae, and shares the clan's five-petaled, star-shaped flowers and milky sap, but the leaves set the species apart: narrow and willowy, and unusually clothed beneath with a grey-white felt, a woolly tomentum that catches the light and lends the whole plant a soft, silvered cast rare in the genus. In spring, clustered flowers of a clean sky-blue open at the tips of the upright stems, quiet and steely and worked over by the first butterflies of the season.
Dwarf bluestar is the compact, well-behaved member of the clan, a tidy mound of upright stems and soft green leaves topped in late spring with clusters of powder-blue, star-shaped flowers. Often treated as a low form of the eastern bluestar, Amsonia montana stays small and shapely, a fine choice where the taller bluestars would sprawl.
