Ceratostigma willmottianum, the Chinese plumbago, is a small deciduous subshrub grown for one of the truest blues in the garden. From midsummer into autumn the wiry, bristly-leaved stems carry clusters of intense cobalt-blue flowers, each a slim reddish-purple tube opening to five pale-blue lobes, and as the season cools the foliage turns a rich red and bronze, so that blue flower and crimson leaf often share the plant at once.
Few native trees announce spring like Cercis canadensis, the eastern redbud, whose bare branches flush rosy pink and magenta weeks before the dogwoods open. The small pea-like flowers cluster not just along the twigs but straight from the older branches and even the trunk, a charming trick called cauliflory, and give way to broad, heart-shaped leaves. A small, graceful understory tree of eastern and central North America, redbud belongs in the legume family, kin to peas and beans.
Cercis yunnanensis, the Yunnan redbud, is an upright, vase-shaped deciduous tree that opens the spring with an abundance of magenta-pink, pea-like flowers, borne in the redbud fashion straight along the bare branches and older wood before the leaves appear. The heart-shaped leaves that follow are the tree's quieter distinction: glossier and more refined than those of most redbuds, giving a polished, clean-textured canopy through summer.
Cestrum elegans var. smithii is the soft, blush-rose form of the elegant cestrum, a fast, arching shrub that carries dense terminal clusters of slender tubular flowers in a warm pink, mildly fragrant in the evening and a steady draw for hummingbirds. Where the species runs to hot red-purple, this variety keeps things gentler, blooming from late spring well into fall, and year-round under glass.
Few plants announce themselves the way Cestrum nocturnum does, and never by daylight. Through the afternoon the shrub keeps to a quiet, almost ordinary green, the slender branches arching and half-climbing, the small tubular flowers furled and unremarkable. Then dusk arrives, the cream-green trumpets open, and the night-blooming jasmine releases a perfume so far-reaching that it carries across a whole garden on still, warm air.
Leatherleaf is the quiet constant of the northern bog. Chamaedaphne calyculata, the only species in the genus, is a low, thicket-forming evergreen of the heath family that ranges right around the cold northern world, from the peatlands of North America east to the bogs of Finland and Japan, and southward in this country to the pocosins and acid bogs of the coastal plain, as far as South Carolina. Across that vast range, leatherleaf forms the dense, spreading colonies that hold a bog together and shelter the wildlife within.
For a week or two in late spring, the Chinese fringetree disappears under snow. Chionanthus retusus var. serrulatus is a deciduous small tree of East Asia, native to China, Korea, and Japan, and the great show is the flowering: dense, lacy, fringed panicles of pure white, each petal narrow and strap-like, smothering the canopy so thickly that the foliage all but vanishes. The genus name says as much, from the Greek chion, snow, and anthos, flower.
The native fringetree is one of the great small trees of the southern spring. Chionanthus virginicus, a deciduous large shrub or small tree, often multi-stemmed, hangs the whole canopy with fleecy, drooping panicles of narrow white petals in spring, soft as torn paper and lightly fragrant, a look that earned the old country names old man's beard and grancy graybeard. On female plants the flowers give way to clusters of raisin-sized, deep blue-purple fruits that birds take quickly.
Chitalpa tashkentensis is a plant with a passport, an intergeneric hybrid that pairs the American desert willow, Chilopsis linearis, with a catalpa, and carries the frilled trumpet flowers of one parent on the willowy, drought-hardy frame of the other. The name itself is a splice, Chilopsis joined to Catalpa, while tashkentensis records the birthplace, the botanical garden at Tashkent, in Uzbekistan, where the cross was raised in the 1960s. From that single Central Asian introduction descend the chitalpas grown across America today.
Choisya is a small genus of aromatic evergreen shrubs from the southwestern United States and Mexico, kin to citrus in the rue family, and Choisya 'Aztec Pearl' is the garden world's favorite of the tribe. The hybrid, a cross between Choisya arizonica and Choisya ternata, was raised by Peter Moore at Longstock Park Nursery in England, and the selection has proved hardier, more heat tolerant, and altogether easier in the garden than either parent.
Cistus x corbariensis is a white rockrose, one of the toughest and most charming of the Mediterranean sun shrubs, covered through late spring and early summer in flowers like small single roses. Each bloom is pure white with a gold eye, the petals crinkled like tissue paper, opening from buds tinged red and lasting a single day before the next takes over. Despite the name, a rockrose is no relation to the true roses, belonging instead to the Cistaceae, the rockrose family of the dry Mediterranean hills.
The rockroses bloom as if for a single day, and in a sense they do. Each papery flower of Cistus x purpureus lasts only from morning to evening before dropping, yet through late spring the shrub opens fresh bloom after fresh bloom, so the whole plant seems perpetually covered. The flowers are the draw: two to three inches wide, crushed-silk petals of pinky purple, each stamped at the base with a deep maroon blotch, a marking that earned the old garden name orchidspot rockrose. Rockroses are not roses, and are not related; the resemblance is only in the open, five-petalled face.
The Rangpur is not truly a lime at all, but Indian gardeners have used the fruit as one for more than five hundred years. Citrus x limonia, an old natural hybrid of mandarin and citron, bears small, round, deep orange fruits that look like tangerines and taste fiercely sour, with the aromatic bite that makes a fine lime substitute for cooking, cocktails, and marmalade. In India the fruit goes by surkh nimboo, the red lime, prized for exactly that intense, tart juice.
Among the very first of the citranges, Citrus 'Rusk' dates to 1897, when Walter Swingle crossed a Ruby orange with the tough, cold-hardy trifoliate orange, Poncirus trifoliata, in the great effort to breed citrus that could take a freeze. The result is a vigorous, tall-growing, notably hardy tree, evergreen to semi-evergreen, and dense with the distinctive three-parted trifoliate leaves.
Named for Walter Tennyson Swingle, the pioneering citrus breeder who spent his career crossing tender oranges with the iron-hardy trifoliate orange, the Swingle citrumelo is among the toughest citrus hybrids ever raised. A cross of grapefruit, Citrus paradisi, and trifoliate orange, Poncirus trifoliata, this vigorous, thorny, semi-evergreen shrub or small tree carries fragrant white citrus blossoms in spring, followed by pear-shaped yellow fruits about the size of a large orange.
Woodlanders has long led in offering citrus and citrus hybrids hardy well beyond the usual citrus belt, and the Troyer citrange is a classic of the kind. A cross of the Washington navel orange and the inedible but iron-hardy trifoliate orange, Poncirus trifoliata, the Troyer was raised in 1909 under the direction of the great citrus breeder Walter Swingle, and later named for A. M. Troyer of Fairhope, Alabama, where the tree first bore fruit, a nice southern footnote for a hardy citrus.
Woodlanders has long led in offering citrus and citrus hybrids hardy well beyond the usual citrus belt, and U.S. 119 is one of the most refined of the group. A complex USDA hybrid, a citrumelo crossed back with a sweet orange, the tree runs one quarter trifoliate orange, one quarter grapefruit, and one half sweet orange, a pedigree chosen to keep the toughness of the trifoliate while pushing the fruit toward genuine quality.
US-942 began life as a rootstock, bred by the USDA and released in 2010 after years of Florida field trials, a careful cross of the Sunki mandarin and the curious Flying Dragon form of trifoliate orange, Poncirus trifoliata. As a rootstock the record is stellar: compact, productive trees, strong resistance to Phytophthora and tristeza virus, and better tolerance of citrus greening than most, which is why growers across the citrus belt have come to trust the number.
The sour orange is grown across the warm world as an ornamental and even a street tree, and stands somewhat naturalized in Florida. The fruit is famous for marmalade and useful little else, since the flesh is fiercely sour and bitter, not for eating out of hand. This particular unnamed selection has a Woodlanders story: we propagated the tree from a single specimen found growing on the edge of an abandoned sandy field in a remote corner of Appling County, Georgia, with no house anywhere near. What drew us was the crop, abundant, large, and very showy, loose-skinned and easy to peel.
Among the more intriguing fruits in the Woodlanders citrus collection, the Gou Tou sour orange stands apart, not only for rarity but for a rare combination of hardiness, heavy fruiting, and surprisingly pleasant flavor. Widely cultivated in Southeast Asia, Citrus aurantium 'Gou Tou' carries the form of a traditional bitter orange but with a taste that leans toward grapefruit, which makes this one of the most palatable sour oranges a gardener outside the subtropics can grow.
