Dogwood

Dogwood - A Plant for all Seasons

No matter where you live in Canada, chances are there is a dogwood for you. Visually appealing and magnets for wildlife, these plants are bound to please both the gardener and naturalist in you.

In general, our native dogwoods have four-season appeal. With spring come flowers, sometimes showy, sometimes fragrant. Summer brings berries that contrast nicely with the leaves. Autumn leaves are eye-catching, with shades of red and orange and, for some species, a late show of bright berries. For one species, at least, snowy winter affords a stunning contrast of bright red branches against the white snow.

What's in a Name?

The origin of the name dogwood is anyone's guess, but two likely theories have been proposed. The first refers to a European species of dogwood (Cornus sanguinea) that was used for making skewers, or daggers, and would have been referred to as dag, dague, or dagge (dagger) in old English. The second theory is based on the reported use of the same species for washing mangy dogs. As for Cornus, it is Latin for “horn” and likely refers to the hardness of the wood.

Appearance
Some species, such as flowering and Pacific dogwood, have showy flowers. The two groundcover species have flowers that are rather inconspicuous but appear magnificent framed by the surrounding large, petal-like bracts. Other dogwoods have clusters of small, creamy-white flowers. Dogwood berries can be bright red, white, dark blue, or even a combination of dark blue and white, as with the silky dogwood. Most species have attractive fall foliage in shades of burgundy, orange, and red.

Uses

Dogwoods have proven to be extremely invaluable to wildlife and humans alike. Shrubby species stabilize slopes and shores, protecting them from erosion. Their branches provide shelter for land and water animals. Dogwood flowers provide nectar to pollinating insects and then become fruit that is sought after by birds and mammals. Even the buds, twigs, and leaves of dogwood are munched on occasionally by local wildlife, although usually not enough to seriously damage the plant.

Depending on where you live, you may look forward to one or many of these visitors to your garden if you plant their favorite dogwood: spruce and ruffed grouse, yellow-bellied sapsucker, wild turkey, woodpeckers (downy, hairy, red-bellied, pileated), great-crested flycatcher, eastern kingbird, tree swallow, thrushes (Swainson's, wood, hermit), American catbird, brown thrasher, cedar waxwing, red-eyed vireo, pine warbler, northern cardinal, white-throated sparrow, evening grosbeak, purple finch, eastern cottontail, chipmunk, white-footed mouse, beaver, black bear, white-tailed deer, and moose.

This hard wooded plant has also attracted human interest. Flowering dogwood, in particular, proved suitable for making bowls, pipes, mallets, golf clubs, and tool handles. Its powdered bark was made into toothpaste and the root bark provided a scarlet dye. Aboriginal people also used red osier dogwood: the bark was smoked in pipes or used to make red dye and the branches were used to make baskets. Dogwoods were also valued for their healing properties — bunchberry for cold and colic remedies; pagoda dogwood for treating sore eyes; and red osier dogwood for treating ailments relating to digestion, eyes, and fever.

(Caution: We are not recommending the use of these plants for medicinal or food purposes. Many plants are poisonous or harmful if eaten or used externally. The information on food and medicinal value is added for interest only. This information has been gathered from books and its accuracy has not been tested.)

Propagation

If you are hoping to encourage your plants in their reproductive efforts, you're in luck. Growing from seed is not very difficult and some species are very obliging with cuttings. Collect and clean berries, separating the seed from the pulp, and plant immediately. Take softwood tip cuttings in the summer, treat with a rooting compound, and plant in a flat for the winter. Shrubby dogwoods that sucker, like the red osier, will propagate from hardwood. Near the end of winter, but before the buds swell, cut a piece long enough to include at least three pairs of buds and place the cut end in soil or water deep enough to cover two of the bud sets. William Cullina of the New England Wild Flower Society recommends starting shrubby species in wet to moderately dry ground and in full sun for dense growth and strong twig colour.

Care

Dogwoods have varied needs, although they tend to prefer sun to partial shade. Some species — such as bunchberry and flowering and pagoda dogwoods — enjoy slightly acidic soil. Most dogwoods enjoy moist soil and grow naturally along the edge of woods or shores. However, some, like the grey and round-leaved dogwoods, tolerate or even thrive in poor soil. All benefit from compost and leaf mould.

The bright red of red osier dogwood stems can fade in the summer months. To encourage bright red new growth, cut back the oldest stems (above a set of buds) in late winter or early spring before the leaves appear.

Flowering dogwoods (C. florida) have had some difficulty with the anthracnose fungus Discula destructiva, also called dogwood blight, which can kill part or, rarely, all of the tree. Symptoms include dieback on the branches in the early summer with dried leaves on twigs. The healthier your trees, the more easily they will be able to ward off this fungus. Keep them healthy by giving them a sunny spot, watering deeply (at ground level) during dry spells, mulching around the trees without touching the trunks, and providing plenty of compost.

 Some Canadian Species

Herbaceous Plants

• Native to: YK, NT, sNU, MB, SK, ON, QC, NB, PE, NS, NL
• Habitat: Found in cool, acidic woods and damp openings. Prefers partial shade and slightly acidic soil but tolerates both dappled and full shade and other soil media. Keep moist.
• Appearance: 4 showy, white, petal-like bracts surrounding small, greenish flowers appear in the early summer followed by bright red berries by late summer. Attractive ground cover growing 7 — 20 cm.

Northern Dwarf Cornel
Cornus suecica

• Native to: nBC, YK, NT, NU, QC, NL, NS
• Habitat: Grows in woods, marshes, and bogs and likes similar conditions to bunchberry.
• Appearance: Like bunchberry, but its showy bracts are pale purplish-white surrounding small, dark purple flowers.

Shrubs

Silky dogwood
Cornus amomum

• Native to: ON, sQC, wNB
• Habitat: Occurring in damp thickets, marshes, and streambanks. Prefers wet soils with full sun to partial shade.
• Appearance: From 1 to 3 m. Small, whitish flowers in flat-topped clusters bloom in early summer. Fruits are dark blue, sometimes with white, appearing by late summer and lasting until early fall. Considered more beneficial for erosion control along shores and for wildlife benefit than for ornamental gardening. Branches red and grey.
• Note: C. obliqua is very similar, but its leaves taper at both ends and are pale beneath.

Red-panicled dogwood, Grey dogwood
Cornus racemosa

• Native to: MB, ON, swQC
• Habitat: Naturally occurring in thickets, streambanks, roadsides, and sandy slopes. Tolerates dry to moist soil, sun to light shade.
• Appearance: Its flowers are whitish and, unlike other dogwoods with flat clusters, appear in long, cone-shaped clusters, blooming late spring to early summer. Light grey branches with white berries on scarlet stems by late summer to late fall. Grows 2 to 4 m, forms compact thickets. Good as a border or screen, sometimes pruned to a tree-like form with a single trunk.

Round-leaved dogwood
Cornus rugosa

• Native to: seMB, ON, QC, NB, NS
• Habitat: Grows in woods and rocky slopes. Tolerates a variety of soils and prefers sun to light shade.
• Appearance: Medium-sized shrub reaching 3 m. Flat-topped clusters of white flowers bloom in late spring to early summer. Light blue/greenish-white fruit appears by end of summer and can last until fall. It is the only dogwood with purple-blotched, greenish twigs.

• Native to: YK, NW, sNU, BC, AB, SK, MB, ON, QC, NL, NB, NS, PE
• Habitat: Naturally grows in moist, open woods; thickets; swamps; and shores. It tolerates sun to light shade and prefers moist soil, even tolerating some standing water, but can adapt to drier conditions. Tolerates a variety of soils.
• Appearance: This vigorous shrub is typically 2 m tall with small, creamy-white flowers in a flat- topped cluster that can bloom anywhere from early summer to
  
  early fall. White berries are present in late summer and fall. Bright red branches on young growth are attractive against winter snow, becoming duller in the warmer months. Lower branches send out white roots or “stolons” into the earth. This is why it is called stolonifera,” bearing stolons”, unlike other dogwoods that grow branches from the main stems. Yellow twig dogwood (Cornus sericea “Flaviramea”) has bright yellow stems.

Small Trees

• Native to: sMB, ON, QC, NB, NS, PE, NL
• Habitat: Naturally grows in many moisture regimes and soil textures but usually along forest edges and streambanks, ravine slopes, and open woods growing beneath larger trees in hardwood and mixedwood stands. It will therefore tolerate sun to light shade and dry to moist soils, preferably slightly acidic. The cooler the climate, the more sun it will need.
• Appearance: A small tree reaching 4 to 7 m, sometimes taller, with flat, fragrant clusters of white flowers that bloom at the end of spring or early summer. Dark blue berries form by the end of the summer. The only dogwood with alternate branching, hence its Latin name, C. alternifolia.

Flowering dogwood
Cornus florida

• Native to: sON
• Habitat: Grows in southern woods. Prefers moist, slightly acidic soil, sun to partial shade.
• Appearance: This small tree of 6 to 12 m has large, showy flowers, either white or pinkish. The flowers last for a couple of weeks in the spring before the leaves emerge. Glossy red berries appear in the fall.

• Native to: sBC (including Vancouver Island, mainland BC, coastal areas, and into the Fraser Canyon).
• Habitat: Found in moist woods and streambanks. Takes sun or shade.
• Appearance: The enormous white blossoms are occasionally pink and grow on 6 — 12 m trees (sometimes taller) with red berries following in early autumn.
• Note: Its flower is the provincial floral emblem of BC.

Images of flowering dogwood courtesy of The Samuel Roberts Noble Foundation, Ardmore, Oklahoma. Visit their Web site at www.noble.org, specifically the Plant Image Gallery. All other species images by Sarah Coulber, with the exception of the bunchberry image, which is by Jim Robertson.

References include The Natural History of Wild Shrubs and Vines by Donald W. Stokes and Weed of the Woods — Small Trees and Shrubs of the Eastern Forest by Glen Blouin.

Native plants add beauty to the garden and provide food for wildlife. Growing them can save both time and money. To learn more about growing native plants in your garden, visit our Get Growing section.

Do you have any wildlife stories, tried-and-true gardening tips, or comments? Please e-mail us, or call Sarah Coulber at 1-800-563-9453 ext. 216 or, in the Ottawa area, at 599-9594.