soils. Tolerates black walnut tree toxicity. Well behaved; provide the trunk with good support. Nature Note: Attracts hummingbirds (p. 91) and butterflies; hosts 19 species of butterflies and moths, including longtailed skippers, silver-spotted skippers, and the marine blue butterfly. Note: Rare or threatened in parts of the Midwest. Zones: (4) 5–9. Confusion Note: Native wisteria is neither CHINESE WISTERIA (W. sinensis) nor JAPANESE WISTERIA (W. floribunda); both invasive plants from Asia are “moderately well behaved” in cool climates “especially if you have a staff of gardeners to pull them off the window screens and telephone wires,” observes William Cullina.38
Marine blue butterfly (Leptotes marina)
Ninebark shrub (Physocarpus opulifolius) Also see p. 268
NINEBARK, ATLANTIC NINEBARK. Family: Rose (Rosaceae). Genus: Physocarpus (P. opulifolius). Height/Spread: 5–10 feet. Ornamental Attributes: Long-lasting, showy white flowers with purple stamens in May to June; long-lasting papery bladder-like red fruit; leaves turn brilliant red, orange, or yellow in fall; exfoliating bark provides winter interest. “Domed clusters of creamy-white flowers smother the even, rounded crowns of ninebark in late spring and early summer,” writes C. Colston Burrell.39 Cultivation: Tough, adaptable to almost all conditions, easy to grow. Full sun to light shade. Dry to moist soil. Tolerates black walnut tree toxicity. Nature Note: Preferred site for many shrub-nesting songbirds. Used for cover, but not food, by deer and rabbits. Nectar and pollen support bees, butterflies, wasps, and the small flies sought by nesting birds. Birds eat the fruits. Ninebark hosts the specialist ninebark calligraphy beetle and 41 species of butterflies and moths, including the dark spotted palthis moth, whose disguise is to look like a leaf. Cultivar/Nativar Note: Although the naturally green-leaved species hosts the specialist ninebark calligraphy beetle,40 the resulting damage is so minimal, experts describe the species as “largely left alone by animal pests.”41 Ninebark cultivars/nativars selected for dark (i.e., purple) foliage all year round instead of the normal green have changed leaf chemistry that makes the leaves indigestible to the ninebark’s specialist beetle.42 Its absence deprives birds of natural food for themselves and their nestlings. Dark-leaved cultivars like ‘Mondo’ Diablo are marketed as “pest-resistant”43 and having “improved disease resistance,” but complaints include fuzzy white coatings, mold, or powdery mildew infecting and killing whole branches.44 Zones: 3–8.
Ninebark flowers (Physocarpus opulifolius)
Giant swallowtail butterfly (Papilio cresphontes)
WAFER ASH, HOPTREE. Family: Citrus (Rutaceae). Genus: Ptelea (P. trifoliata). Height/Spread: 10–20 feet. Multistemmed shrub or small tree. Ornamental Attributes: Pretty clusters of fragrant small greenish-white flowers in April; dark green trifoliate leaves turn yellow in fall; showy flat, wafer-like winged fruits provide winter interest, as does the slender crooked trunk with interwoven, ascending branches. Good as a specimen or screen. Cultivation: Sun, light shade; moist, humus-rich, well-drained soil. Hardy and easy-care. Wafer ash does not belong to the ash family, so isn’t subject to their destruction by emerald ash borers. Its fruits resemble elm seeds, but it is not an elm, so not subject to Dutch elm disease. Nature Note: Wafer ash hosts 6 species of butterflies and moths. Along with pricklyash (Summer Shrubs, p. 124), wafer ash hosts the giant swallowtail butterfly. The moths it hosts include the brown-bordered ermine. The two-marked treehopper, whose frothy white egg masses are visible in winter, also relies on the wafer ash. Pollinators include small bees, wasps, flies, and ants that feed primarily on nectar. Songbirds use it for nesting. Note: One of Christopher Starbuck’s selections for uncommon trees for specimen planting. Zones: 3–8.
More Native Alternatives:
AMERICAN BLADDERNUT, p. 41; AMERICAN SMOKETREE, p. 65; BLUEBERRY SPP., p. 27; CHOKEBERRY SPP., p. 13; DOGWOOD SPP., p. 48; ELDERBERRY SPP., p. 29; FOTHERGILLA SPP., p. 27; GOLDEN CURRANT, p. 35; OZARK WITCH HAZEL, p. 75, RHODODENDRON, AZALEA SPP., p. 56; SCENTLESS MOCK ORANGE, p. 46; SPICEBUSH, p. 22.
See Summer Shrubs for BUTTONBUSH, p. 131; HYDRANGEA SPP., p. 143; NEW JERSEY TEA (WILD LILAC), p. 134.
See Spring Trees for AMERICAN PLUM and other native plums, p. 78; CAROLINA SILVERBELL, p. 80; CHOKECHERRY, p. 83; FRINGE TREE, p. 105; SASSAFRAS (SHRUB FORM), p. 99; SERVICEBERRY SPP., p. 20; YELLOWWOOD, p. 96.
Sweet mockorange (Philadelphus coronarius)
Nonnative:
MAGNOLIA. See Spring Trees, p. 109.
Nonnative:
MOCKORANGE, SWEET MOCKORANGE. Family: Hydrangea (Hydrangeaceae). Genus: Philadelphus (P. coronarius). Origin: Europe. Height/Spread: 8–10 feet. Ornamental Attributes: White flowers in late spring to early summer, sometimes fragrant. Lanky plants with nondescript foliage. “To avoid disappointment it is well for the fragrant-minded to realize that many Philadelphus have no perfume, ‘scentless, or souless . . . beautiful and dumb’ in Mrs. [Louise Beebe] Wilder’s words,” wrote Wilson and Bell.45 No fall color. Cultivation: Full sun to light shade, medium soil. Ecological Threat: Naturalized in midwestern states. Zones: 5–8.
