February 2023: Redosier Dogwood

Redosier dogwood in flower. This shrub is beautiful in all seasons and is highly beneficial to birds. Photo: Cephas, CC BY-SA 4.0

The Homegrown Habitat feature provides advice on what and where to plant, one per month, written by Sarah W. Middeleer, a landscape designer whose work focuses on ecology and designing for wildlife. Sarah serves as vice chair of the Connecticut Audubon Board of Directors. Write to her at homegrown@ctaudubon.org.

Redosier dogwood (Cornus sericea), also known as red-twig or red-stem dogwood, is a handsome shrub form of the genus Cornus.

You may be more familiar with one of the tree forms, flowering dogwood (Cornus florida), a popular native tree. It has two close cousins in New England, silky (C. amomum) and gray (C. racemosa) dogwoods, but redosier has the best winter interest.

This large shrub displays garnet-colored stems in the coldest months, making it a standout in the winter garden — especially with a backdrop of conifers and other evergreens. Of course it is also gorgeous in the snow.

Small, white, fragrant flowers in umbrella-like clusters known as cymes appear in late spring and early summer. They develop into the white berry (technically drupe) clusters. Sometimes these showy fruits will have a bluish tint. Fall foliage ranges from orange-red to purple.

The fruit of the dogwood genus (Cornus) is eaten by at least 95 species of birds, including Ruffed Grouse, Will Turkey, grosbeaks, Brown Thrashers, waxwings, and Gray Catbird. Redosier fruit is eaten by at least 18 of these species.

Several butterflies and moths utilize redosier, including the definite tussock moth and the royal walnut moth (intriguingly called hickory horned devil in its larval form). The lepidoptera lay eggs on this obliging host. When the eggs hatch, songbirds scoop up the nutritious caterpillars to feed their young.

Redosier dogwood in winter. Photo: USDA-NRCS PLANTS Database / Herman, D.E. et al. 1996.

Redosier is said to be deer resistant, but deer may browse on new growth.

Redosier’s stems develop their most brilliant color when cold weather sets in. The younger stems redden more than the older ones so, although pruning isn’t necessary, some gardeners will thin out older stems from the base of the plant. Others sometimes cut back the entire shrub severely in the fall, so that all of the next year’s growth will be red.

This pruning approach, however, will not foster the redosier’s graceful natural shape nor its ability to offer birds protectively dense cover.

Use redosier dogwood as a hedge, part of a shrub border with evergreens, in a woodland or winter garden, or even as a specimen. It is terrific in hedgerows due to its tendency to form dense thickets, a boon to birds looking for protective nesting sites. If necessary, inhibit its proclivity to spread by cutting away the spreading runners with a sharp spade. But its fibrous root system makes redosier ideal for holding slopes and preventing erosion. It also makes an excellent rain garden plant.

Redosier prefers moist to wet soils and is often found in boggy areas in the wild. However, it will tolerate a wide range of soils, including clay, drier areas, and either alkaline or acidic soils. It is the most widespread dogwood, occurring in almost all of North America save for the southern Great Plains and the southeastern U.S.

Planting redosier in full sun will result in maximum flowering, fruiting, fall foliage color, and winter stem color–but it will certainly tolerate partial shade. I mistakenly planted one in quite heavy shade, and it still puts out gorgeously red branches but doesn’t produce many flowers or fruits.

At least 95 bird species eat redosier dogwood fruit. Photo by Andrea Moro, CC BY-SA 4.0

Redosier grows quickly to 7-9 feet high by about 7-10 feet wide and, with room, will develop an attractive vase-shaped habit with spreading, arching stems. Its natural companion plants include spicebush, button bush, Carolina rose, pussywillow, wild ginger, sweet flag iris, jack-in-the-pulpit, meadow rue, Virginia bluebells, ferns, and violets.

Native Americans are said to have used the inner bark in tobacco mixes (one source reports that it has a narcotic effect). Redosier branches were made into arrow shafts, bows, and baskets. Its leaves, bark, and roots were used to make medicines. Current basketmakers may be interested to learn that if redosier twigs are harvested in early spring, they will retain their red color even after they have dried.

Confusingly, a few years ago genetic botanists gave the shrub dogwoods a new genus name, Swida. Yet most sources still use the Latin name Cornus sericea.

An Asian import called Siberian dogwood (Cornus alba), is also called red-stemmed dogwood. And cultivars of Cornus sericea, as well as C. alba abound, some with yellow branches and variegated leaves.

But try to get this fine shrub in its original species form. It will reward you with winged and squirmy visitors of great interest and will brighten up even the dreariest of February days.

Lest you think botanists are humorless folk fixated on nomenclature, I close with a botanical joke, courtesy of the U.S. Forest Service Plant of the Week webpage:

How do you tell it is a dogwood?

By its bark, of course!

As always, we welcome inquiries and comments!