Caryopteris x clandonensis 'Dark Knight' (Dark Knight Bluebeard, Dark Knight Blue Spirea, Dark Knight Blue-Mist Shrub)

Michael's Opinion

Caryopteris x clandonensis ‘Dark Knight’ is a low growing shrub commonly used in grouping, massing and as a border shrub, but is uncommonly used as a ground cover or small informal hedge. Bluebeard flowers with an exhilarating deep blue to purple in a cyme arrangement in a whorled pattern with both scented flowers and leaves. It is drought tolerant as well as pH adaptable and slightly urban tolerant but is intolerant to poorly drained soil conditions. Though Bluebeard is a slow growing shrub it benefits from being pruned back during early spring or late autumn to allow for new vigorous growth to develop. The flowering period will not be affected due to pruning because flowering will then take place on new growth.

Botanical Information

FamilyLamiaceae (Verbanaceae)
GenusCaryopteris
Speciesx clandonensis
Cultivar'Dark Knight'
CategoryWoody
TypeShrub (deciduous)
ReferencesDolezal, Robert J. The Complete Guide to Choosing Landscape Plants. Minnesota: Creative Publishing International Inc., 2002. Print. Better Homes and Gardens. Perennial Gardening. New Jersey: John Wiley and Sons Inc., 2010. Print.

Details

USDA Hardiness Zone5 - 8
USDA Hardiness Ref.
Canadian Hardiness Zone6 - 9
Canada Hardiness Ref.
RHS Hardiness Ref.
Temperature (°C)-18 - (-23)
Temperature (°F)0 to (-10)
Height150 cm
Spread90 cm
GrowthSlow
Flowering PeriodJuly, August, September

Description and Growing Information

General DescriptionA low maintenance, low growing shrub with both fragrant leaves and flowers. Bluebeard flowers between the months of July to September.
ID CharacteristicDark blue flower, dull green leaves with a silver underside. Fragrant flowers and leaves when crushed.
ShapeLow grown mounded shrub.
LandscapeLow growing shrub used in massing, grouping or as a border. Uncommonly used as a ground cover or small informal hedge.
PropagationStem cutting collected from desirable plant containing an apex or node capable of rooting should be treated with a rooting solution. Place into a container of well composed soil and apply a complete fertilizer with a high level of nitrogen.
CultivationGrows well in full sun, well drained to moist soils in a variety of soil types. PH adaptable and somewhat urban tolerant. Should be planted at least a meter apart, and the soil should be allowed to dry between watering.
PestsPest and disease resistant. Poor drainage may result in the rotting of the root crown.
Notable SpecimensMissouri Botanical Garden, St.Louis, Missouri., USA
HabitatHortiticultural origin.
Bark/Stem DescriptionDeep green that is dull in colour but has a smooth thin outer bark. Scented.
Leaf DescriptionOvate to lance shaped simple leaf with opposite arrangement. 10 cm in length. Dull green with a silver underside. Scented.
Flower DescriptionDeep blue to purple coloured flowers on the terminal and axillary cyme arranged in a whorled pattern.
Colour DescriptionDark blue to purple flower. Dull green with silver underside leaf. Deep green bark.
Texture DescriptionNo change between seasons. Medium leaf with fine stems.

Photographs