Common Name: red twig dogwood
Type: Deciduous shrub
Family: Cornaceae
Zone: 3 to 8
Height: 4.00 to 5.00 feet
Spread: 4.00 to 7.00 feet
Bloom Time: May to June
Bloom Description: White
Sun: Full sun to part shade
Water: Medium to wet
Maintenance: Medium
Suggested Use: Hedge, Rain Garden
Flower: Showy
Leaf: Good Fall
Attracts: Birds, Butterflies
Fruit: Showy
Other: Winter Interest
Tolerate: Deer, Erosion, Clay Soil, Wet Soil
Culture
Best grown in organically rich, fertile, consistently moist soils in full sun to part shade. Tolerant of a wide range of soils, including swampy or boggy conditions. Trim roots with a spade and promptly remove root suckers if colonial spread is undesired. Best stem color occurs on young stems. Although pruning is not required, many gardeners choose to remove 20-25% of the oldest stems in early spring of each year to stimulate growth of new stems which will display the best color. As an alternative to annual pruning, some gardeners prune all stems close to the ground (coppice to 8") in early spring every 2-3 years to renew. Any loss of flowers through spring pruning is not terribly significant since the small flowers of this dogwood are rather ordinary. Plants become stressed and more vulnerable to diseases such as canker in hot and humid summer climates south of USDA Zone 7.
Noteworthy Characteristics
Cornus sericea, commonly known as red twig dogwood or red osier dogwood, is an upright-spreading, suckering shrub that typically grows in the absence of pruning to 6-9’ tall with a slightly larger spread. With the exception of the lower midwest and deep South, this species is native to much of North America where it is typically found growing in wet swampy areas, wetland margins or along lakes and rivers. Ovate to lanceolate, medium to dark green leaves (2-5” long) acquire interesting shades of red to orange eventually fading to purple in autumn. Reddish stems turn bright red in winter and are particularly showy against a snowy backdrop. Tiny, fragrant, white flowers appear in flat-topped clusters (cymes to 2.5” diameter) in late spring, with sparse, intermittent, additional flowering sometimes continuing into summer. Flowers give way to clusters of whitish (sometimes with a bluish tinge) drupes in summer. Fruit is quite attractive to birds and is generally considered to have as much if not more ornamental interest than the flowers.
Red stems somewhat resemble the reddish stems of some osier willows, hence the common name of red osier dogwood. Some cultivars of this species (e.g., C. sericea 'Flaviramia') have yellow stems.
Synonymous with and formerly known as Cornus stolonifera.
Genus name comes from the Latin word cornus meaning "horn", possibly in reference to the strength and density of the wood. Cornus is also the Latin name for cornelian cherry (Cornus mas). May also be related to the Greek kerasos meaning "cherry".
Specific epithet from Latin means silky in reference to the hairs present on young twigs and upper leaf surfaces.
'Isanti' is a rapid-growing, multi-stemmed, deciduous shrub which grows to a maximum size of 4-5' tall with a rounded, spreading (stoloniferous) habit. Denser and more compact than the species due in large part to its shorter internodes. The outstanding ornamental feature of this plant is its bright red winter stems.
Problems
Susceptible to leaf and twig blights, canker and leaf spots. Scale, leaf miners and bagworms are occasional insect pests.
Uses
Excellent massed or as a specimen. Effective in shrub borders where plants can be combined with evergreens or a contrasting color of redtwig dogwoods for interesting winter contrast. Also effective in naturalistic plantings in moist soils where plants can be allowed to spread and form thickets. Plants perform very well in wet locations such as low spots or along streams or ponds where spreading roots can help combat soil erosion. May also be used as a property line screen.
Can be combined with yellowtwig dogwoods (e.g., Cornus sericea 'Flaviramea') for an interesting bicolor winter stem display.