Shrub Dogwoods for the Home Landscape

When someone mentions the plant "dogwood," most people automatically think of the flowering dogwood (formerly Cornus florida). It is the most prominent of the dogwoods in the landscape, with its stellar performance as a small flowering tree. It was also the first dogwood collected and sent to Europe as early as 1731. Gardeners have since included Cornaceae's other species (and genera) into the home landscape. Shrub dogwoods offer four-season interest for the home gardener, from spring flowers, fruit, and foliage in the summer, autumn leaf color, to colorful winter bark and fruit retention. Each species listed below is native to Pennsylvania and provides beauty and wildlife benefits. As shrub dogwoods have gained popularity, so too has the cultivation of their unique characteristics. The University of Connecticut Plant Database and the North Carolina Extension Gardener Plant Toolbox offer a current list of native cultivars of dogwoods.

The author mentioned that the flowering dogwood was formerly known as Cornus florida. Yes, this is correct. This tree now has the scientific name Benthamidia florida, but why? In the early 2010s, taxonomists found genetic differences that were significant enough to split Cornus into four genera: Cornus (Cornelian cherries), Benthamidia (big-bracted dogwoods); Swida (white- and blue drupe dogwoods), and Chamaepericlymenum (dwarf dogwoods). Using the genus, Cornus is still widely accepted in horticulture circles for all dogwoods. It will take time for arboretums, gardens, and nurseries to make the changes. This article includes both the new and former scientific names of dogwoods.

The silky dogwood (Swida amomum; formerly Cornus amomum) range starts north in Newfoundland and Ontario and makes its way down through the eastern and central parts of the United States to Florida and Alabama. A late spring bloomer with creamy-white flower clusters, the silky dogwood reaches 12 feet tall and 12 feet wide with a multi-stemmed habit. The azure butterflies (Celastrina spp.) use silky dogwood as a larval host plant. From August to September, fruits in the form of round white drupes are on display, turning bluish-purple as they ripen. Many songbirds and small mammals consume these fruits. Site in a well-drained medium to wet acidic soil in partial shade to full sun. The shrub can tolerate full shade conditions but will show signs of stress when the roots begin to dry. Apply mulch 2 to 4 inches thick around the plant to protect the roots from drier conditions. Due to its multi-stemmed nature, silky dogwood works well en masse or as a hedge. Silky dogwoods propagate easily by layering.

Gray dogwood (Swida racemosa; formerly Cornus racemosa) may appear a little subdued compared to other members of the dogwood family, according to some gardeners. What it lacks in flare, it makes up in adaptability as a hedge, border, erosion control, along ponds and streams, or even in meadows. One cannot say it doesn't try to put on a show. Younger stems have a reddish tinge, the fall foliage is reddish-purple, and the prominent red fruit pedicels remain throughout the winter. As with other dogwoods, the fruits are white drupes and are vital to a diversity of wildlife, including northern bobwhites, woodpeckers, and grosbeaks. The shrub is a host plant for the caterpillars of the spring azure butterfly (Celastrina ladon). Gray dogwood ranges from Canada along the eastern part of the United States to South Carolina and over to North Dakota and Texas in USDA Plant Hardiness Zones 4 through 8. It is found in various habitats and is tolerant of many soil conditions, from moist and wet to dry and differing light conditions: full sun to partial shade. Gray dogwood can grow tall, up to 27 feet, and can easily be trained into a small tree.

Red-osier dogwood (Swida sericea; formerly Cornus sericea) quickly becomes a favorite in the home landscape as it stands out by living up to another of its common names—red twig dogwood. The bright red twigs on this multi-stemmed shrub provide aesthetic interest all year round. The most vivid color occurs on the young stems. Therefore, pruning back older branches in early spring stimulates new vigorous growth. Early summer brings white flower clusters that give way to white drupes. The green foliage changes to red and purple in the autumn, again making it an excellent specimen for the garden. Red-osier dogwood stays between 6-9 feet in height. However, it will spread in width, up to 10 feet, and by suckers. A former specific epithet for the shrub was stolonifera, meaning bearing runners. If unwanted, the runners are easily deterred by a sharp spade. Allowing this shrub to spread will make a nice border or screen. Make sure to site the red-osier dogwood in moist, well-drained soil in partial shade to full sun. Deer rarely browse this shrub except during harsh weather conditions. The white drupes are a significant resource for wildlife, and the leaves are a food source for spring azure butterfly caterpillars (Celastrina ladon).

Bunchberry (Chamaepericlymenum canadense; formerly Cornus canadensis) is quite different from the other dogwoods, as it is more of a groundcover than a shrub, reaching only 6 to 12 inches in height. Bunchberry makes a delightful addition to the home garden. The flowers are reminiscent of its taller family member, the flowering dogwood, bearing four white ovate bracts during the spring. Bright red drupes follow and persist through autumn until devoured by the birds. Bunchberry is finicky outside its natural range from the northern mixed forests of Canada south through Virginia. Mimic this habit with dappled sunlight to partial shade in areas without foot traffic so the bunchberry can spread via rhizomes. Cool, damp, and acidic soils will allow this shrubby groundcover to thrive in USDA Plant Hardiness Zones 2 through 6.