Learn about several plant varieties and the planting information for each zone.
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Best foliage color is in full sun
Plant in rich, but well-drained soil
Water regularly until established; fertilize in spring; prune after flowering if needed
Height: 4-6 feet; Width: 4 feet
Hardy in USDA zones (4)5-8(9):
Zone 4: Plant in spring; plant in full sun; mulch heavily after first hard frost to prevent winter heaving; avoid contact with salt; may be marginally hardy in this zone.
Zone 5: Plant in spring; plant in full sun; mulch heavily after first hard frost to prevent winter heaving; avoid contact with salt.
Zone 6: Plant in spring or early fall; plant in full sun; mulch in fall.
Zone 7: Plant in early fall; plant in full sun; mulch in fall.
Zone 8: Plant in early fall; plant in full sun; mulch in fall.
Zone 9: Plant in early fall; plant in full sun; mulch in fall; may languish in this warmer climate.
Buddleia davidii 'Black Knight' – Black Knight Butterfly Bush
Gardener's Note: This plant is on the watch list of several Western and Midwestern states for possible invasiveness.
Deciduous shrub with gray-green foliage and dark purple flowers that attract butterflies
Plant in rich, but well-drained soil; prune heavily in very early spring
Water regularly until established; fertilize in spring
Deadhead to reduce seedlings and prolong blooming
Plant in full sun for best flowering
Height: 8-10 feet; Width: 6-8 feet
Hardy in USDA zones 4-9:
Zone 4: Plant in spring to prevent winter heaving; plant in full sun; mulch heavily after first hard frost; avoid contact with salt; care for plant as herbaceous perennial and prune to the ground in early spring; may be marginally hardy in this zone.
Zone 5: Plant in spring to prevent winter heaving; plant in full sun; mulch heavily after first hard frost; avoid contact with salt; care for plant as herbaceous perennial and prune to the ground in early spring.
Zone 6: Plant in spring or early fall; plant in full sun; mulch in fall; care for plant as a deciduous shrub and prune heavily in late winter.
Zone 7: Plant in early fall; plant in full sun; mulch in fall; care for plant as a deciduous shrub and prune heavily in late winter.
Zone 8: Plant in early fall; plant in full sun; mulch in fall; care for plant as a deciduous shrub and prune heavily in late winter.
Zone 9: Plant in early fall; plant in full sun; mulch in fall; care for plant as a deciduous shrub and prune heavily in late winter.
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