Cornus 'Kn30-8' (Venus Flowering Dogwood)


Michael's Opinion

Cornus ‘Kn30-8’ Venus or the Venus Dogwood has much to offer as a specimen tree; As a cold hardy hybrid it possesses large flowers that could rival a magnolia for spring interest and majesty while rivalling a crabapple for colourful fruit and interesting autumn colour. As well, the flowers not only look beautiful, they also attract pollinators of many species and hold a tasty fruit for those furry and feathered friends who stay up north during the fall and winter months. The venus dogwood has been selectively hybridized to be resistant to diseases which are commonly known to plague dogwoods as well as also being tolerant somewhat drought tolerant.

Botanical Information

FamilyCornaceae
GenusCornus
Cultivar'Kn30-8'
SynonymsCornus kousa 'Venus'
CategoryWoody
TypeTree (deciduous), Shrub (deciduous)
OriginThe venus dogwood is a hybrid of the dogwood species Cornus kousa variety-chinensis x Cornus nuttalii ‘Goldspot’ x Cornus kousa 'Rosea', Cornus kousa being native to Japan, Korea, and China; Cornus nuttalii however being native to the west coast of North America, growing from British Columbia to California. Cornus venus ‘Kn30-8’ was brought to the market by Rutgers University, and was part of the Jersey Star series of dogwoods which was produced by Elwin R. Orton, Jr. In 2007 the venus dogwood won the “best novelty of the year award” at the plantarium in the Netherlands and in Germany in 2008, as well as in 2009 the venus dogwood also won the grower of the year award.
Ethnobotanical Uses
Disclaimer
The venus dogwood is best used as a specimen tree or in small groups as an accent cluster for spring flower interest.

Details

USDA Hardiness Zone7b - 8a
USDA Hardiness Ref.
Canadian Hardiness Zone7b
Canada Hardiness Ref.
RHS Hardiness ZoneH5
RHS Hardiness Ref.
Temperature (°C)-15 to -10
Temperature (°F)5 - 14
Height5-6 m
Spread5-6 m
GrowthMedium
Flowering PeriodApril, May

Description and Growing Information

General DescriptionA deciduous, mounding tree with large white flowers in the spring, which later grow into large red berries in the summer and autumn. Cornus ‘Kn30-8’ has a notable red/orange autumn colour with crinkled leaves resembling Cornus kousa.
ID CharacteristicCan be best identified by its large white, bract like flowers, mounded shape, elliptic-ovate leaves, and red/orange autumn colour. As with most examples in the cornaceae family it grows best in moist soil, in an understory or partial shade setting. Venus Dogwood has also been noted to have a higher than average tolerance for drought as well as a resistance to several Cornus specific diseases and predators.
ShapeHeavily mounding form, with low growing branches as well as vertical branches.
LandscapeCornus ‘Kn30-8’ is best used as a specimen tree or used in a small group as an accent planting in a shaded and sheltered area. The plant has multiple, season interest, with large white flowers in the spring, turning into bright pink/red berries during the summer season. Finally, turning a bright red/orange colour in the autumn.
PropagationPropagation is done in two ways: grafting, or budding. Grafting, is done by taking a branch cutting from an existing Venus dogwood and reattaching said cutting onto the rootstock of a hardy selection of Cornus kousa, which has a USDA zone hardiness of 4-8, allowing for Cornus ‘Kn30-8’ to survive in a wide temperature range. Budding, is more commonly employed as it uses less vegetative material than grafting with the same outcome. Instead of a full branch cutting being taken, a single bud is attached to the selected root stock, allowing for more product to be created. Budding can be done in spring, or summer with summer being the ideal time to do budding as the root stock will be more likely to grow around the bud at this time, and the bark will be more manageable when attaching the bud to the rootstock.
CultivationBest grown in partial shade but can handle full sun; sheltered areas that allow for well drained, moist soil. The Venus Dogwood prefers acidic soil heavy in organic matter. It is noted to have good drought tolerance, however, it can not go for extended periods of time without a water source.
PestsCornus ‘Kn30-8’ has been hybridized to be resistant to deer as well as many dogwood specific diseases such as anthracnose and powdery mildew, both diseases which commonly plague the Cornaceae family. The Venus Dogwood’s resistance is not perfect however and it can develop said diseases if the tree experiences high levels of stress or abnormal growing conditions are present.
Notable SpecimensSpecimens can be found in the Exbury gardens in Hampshire, England. Rutgers University in New Jersey, United States of America, (where the Venus dogwood was first developed).
Bark/Stem DescriptionThe bark tends to exhibit a darker sand brown with lighter brown tones showing through exfoliated bark on older growth while young growth showing more of a mix of light grey and crimson brown tones.
Flower/Leaf Bud DescriptionFlower buds form at the end of stems, with two bud scales meeting in a point at the top of the bud, the flower buds are a light green with a lantern like form and are 2-3 cm in size.
Leaf DescriptionLeaves are opposite, elliptic-ovate, simple in shape. The leaves grow to be 4-8 cm long and 2-4 cm at the widest point and are thick and glossy.
Flower DescriptionFlower buds open into four light green bracts which fade to a bright white as the flower grows, growing in size to 15 cm across. The 1.5 cm, light green flower blooms in the centre of the four bracts with several small white anthers growing from the flower. The venus dogwood, when in bloom, often can be seen covered in white flowers making it a perfect specimen tree.
Fruit Description2-3 cm fruit resembling the shape of a raspberry hang from 4-5 cm stocks, dark pink to dark red in colour, fruit forms in August through to October.
Colour DescriptionCornus ‘Kn30-8’ develops a bright red to red orange autumn colour which compliments the bright red fruit which cover the tree at the same time.
Texture DescriptionOld growth has a coarse texture with exfoliated bark while new growth has a fine texture with smooth bark.

Photographs