Buddleja macrostachya (Syn. Buddleja cylindrostachya, Buddleja hookeri) | Long-spiked Butterfly Bush
An exotic alternative to the more common Buddleja species, Long-spiked Butterfly Bush is native to East Himalaya to South Central China and North Indo-China, where it grows as a large woody shrub as hillside scrub and in forest clearings, and are usually found at altitudes greater than 3,000+ ft. Plants have evolved at altitude, so are suited for temperate mountainous habitats. Full sun is best, but don’t like to be too hot. They require humus-rich, moisture retentive soil in summer and well-drained soil in the winter. Sheltering plants from the harshest winds and avoiding planting in frost pockets should insure the plants make it through winters. Adding a good layer of winter mulch on top of the roots helps protects the soil from freezing solid. Fully root hardy to at least zone 8 (10 degrees F). If plants die to the ground they will shoot up to 8-9 ft by autumn.
The naturally occurring plants of this species are highly variable in structure, flower color, hardiness, and bloom period, but the ones we have were wild-sourced from China and are upright plants with huge deep-green, leathery leaves, and large, pink, violet-mauve, or deep purple upright flowers with bright eyes that bloom after a hot summer in late-summer or autumn, and occasionally in late-winter/early-spring.
Rare in cultivation.
Sun Exposure: Full sun
Mature height: 8-12 ft
Mature width: 4-6 ft
Hardiness zones: 8-11