You do not need to be a native plant purist to understand the importance of including native plants in an ecologically functional garden. The four native shrubs discussed below provide colorful flowers and fruits for the gardener’s enjoyment as well as food and shelter for wildlife, including insects and birds.
Blooming in early June along roadsides, in the low ground of open coniferous woods, in local swamps, and on dry sandy hillsides and rocky upland barrens, black chokeberries (Aronia melanocarpa) fill the air with a musky sweet scent. In these wild places they seldom exceed three feet in height, but in the garden, growing in full sunlight with their roots in compost-enriched soil, they reach a height of six feet.
Suckering profusely, each black chokeberry shrub consists of multiple slender stems held stiffly erect, the upper two-thirds covered in glossy dark-green leaves frosted with white flowers. The five petals of each half-inch flower surround a cluster of pink anthers held high on extended filaments.
The flowers are foraged by several pollinator species. Once, in a few minutes of close observation, I recognized two different species of bumble bee, two different fly species, a tiny wasp of unknown identity, and several different solitary bee species, all moving chokeberry pollen around as they went about their foraging.
From early September to late November, the shrubs bear loose clusters of glossy black berries, fruits that contain higher levels of antioxidants than any other temperate fruit, including blueberries. This feature has prompted increasing interest in black chokeberries among small fruit growers in the United States. Whole berries are canned, the juice is used in making jelly or added to apple juice, and extracts of the berries are used as natural colorants in other foods.
In the wildlife garden, black chokeberries are eaten by grouse, black-capped chickadees, cedar waxwings, black bears, red foxes, rabbits, and white-footed mice. I read that the astringent taste of the berry (the characteristic responsible for its common name) makes it a food of last resort among winter birds. I have noticed that many berries do shrivel on the stems, but I have also watched winter robins feast on ripe chokeberries when other fruits were still locally abundant.
A. melanocarpa is native throughout the eastern half of the United States. As a landscape plant, its merits have been sung since its introduction to Western gardens in the 1700s. In 1972, black chokeberry received the Royal Society’s Award of Merit and was described as a “splendid shrub for naturalistic plantings, especially on the edge of woodlands.” Others have recommended it for use in mass plantings, informal hedges, pond plantings, and as a spot of color in a mixed border.
Few other native shrubs are as ornamental, stress tolerant, and ecologically functional. Native to much of eastern North America, diervilla (Diervilla lonicera) is a beautiful flowering native shrub with a most unfortunate common name, northern bush honeysuckle. It is not a honeysuckle and should not be confused with the non-native invasive shrubby honeysuckles. Ask for it by scientific name, not by common name.
A small deciduous shrub typically growing to three or four feet tall (occasionally to six feet), diervilla has an upright arching and spreading habit. The new light green leaves emerge in mid-May, gradually turning to a dark green as the weather warms. If it stays cool and wet, the newest summer leaves display a unique pattern of light green and auburn. In autumn, the leaves turn first to yellow, then orange, and finally red. Diervilla is one of our garden’s loveliest fall shrubs.
Diervilla’s first flowers, funnel-shaped bells about a half-inch in length and clustered in the leaf axils, first appear in late June and blooming continues through July. Pale yellow at first, the flowers slowly turn to orange or purplish red as they mature. They provide steady forage for native pollinators, particularly bumblebees, during a time of the year when few other plants are flowering.
Thriving in either sun or shade, diervilla is extremely drought tolerant and can be used in soils ranging from course sands to heavy clays. It is not tolerant of flooding, however, so do not plant it in low areas where snowmelt and early spring rain create seasonal ponds.
We purchased our diervilla plants in one-gallon containers, well-established plants that had already developed rhizomes, and planted them three to four feet apart on both sides of the steps leading up to the house. After a single growing season, shoots from the underground stems had emerged to fill in the spaces between plants. By the end of the second summer we had what we had envisioned, a continuous thicket of foliage and flower that not only holds the soil together but provides ornamental beauty from May to November. Even the plant by the driveway that gets whacked by the snow plow every winter is quick to recover.
You will not find rugosa rose (Rosa rugosa), often called beach rose, on a list of plants native to North America. Many people believe it to be native and are astonished when they learn that it is a non-native invasive species. And I’ve heard otherwise sane folks say that the invasion of beach rose is over, that it now occupies every possible coastal site where it can grow, therefore we need not worry over it anymore.
Not true! Over my 15 years in Maine, visits to the island village of Vinalhaven have revealed continuing encroachment of beach rose into the surrounding native landscape. In the open fields bordering the rocky coastline, I see colonies of beach rose expanding, swallowing up space previously occupied by native plants such as northern bayberry, meadowsweet, sweet fern, and native rose. No doubt this invasion began as seeds from garden plants in the village were dispersed by birds.
Despite its beauty, beach rose should be viewed as a serious threat to the integrity of all coastal plant communities. There are still areas of New England that can be protected from the invader and other areas that can be reclaimed, but only if we stop growing beach rose in our gardens.
There are beautiful alternatives. Chief among them are two very similar native rose species, R. carolina and R. virginiana. No, they are not as fragrant as beach rose, nor as long-flowering, and they have simpler flowers, a single row of pink petals surrounding bright yellow stamens. But their autumn display of burgundy-red foliage and deep red hips more than compensate.
Native throughout the eastern United States, the Virginia rose (Rosa virginiana) has lovely deep pink summer flowers that provide pollen and nectar for flower beetles, solitary bees, and other pollinators. In autumn, the dark red hips are eaten by song birds, game birds, rodents, and small mammals.
A denizen of meadows, pastures, and roadsides of the eastern United States, meadowsweet (Spiraea alba var. latifolia) begins to bloom in May and continues flowering through August. Its small soft pink flowers, borne in terminal branched clusters, are pollinator magnets throughout the summer. In autumn, the leaves turn to tarnished gold and in winter the pale brown to red-brown seed heads float shadows on the garden’s blanket of snow.
In a comprehensive study of native plants conducted by Michigan State University, meadowsweet was the third most attractive plant to beneficial predator insects and spiders, over four times as effective in attracting predators as a grass control. Beneficials attracted by meadowsweet included both crab and jumping spiders; soldier beetles that eat aphids and other insects; plant bugs that prey on leaf beetles; damsel bugs that prey on aphids, leafhoppers, mites, and caterpillars; lady beetles important in controlling aphid populations; and ichneumonid wasps, parasitic wasps that prey on beetles and caterpillars.
In the same study, meadowsweet attracted moderate numbers of bees, including bumblebees, sweat bees, and andrenid bees, very common spring pollinators in New England.
Beginning in May with the first flowers of meadowsweet and ending with the frosted hips of Virginia rose, these native shrubs enhance the beauty of our gardens with foliage and bloom while nourishing a wide variety of garden wildlife. You cannot ask more of a garden plant.