Culture
Grow in average, medium moisture, well-drained soil in full sun. Becomes weedy and sparse with diminished flowering performance if not grown in full sun. Does poorly in wet, poorly draining conditions. Will adapt to clay soil if properly amended. Removal of spent flower spikes during the growing season will encourage additional bloom. This hybrid is one of the least winter hardy of the buddlejas, and is only recommended for growing in USDA Zones 6-9. Therefore, in order for this plant to survive in the St. Louis area (Zone 5b-6a), it should be grown in a protected location with a winter mulch. Regardless of winter protection, in Zone 6 the top growth of this plant may die to the ground in winter with roots surviving. Even if plants do not die to the ground, they usually grow more vigorously, produce superior flowers and maintain a better shape if routinely cut back to a framework close to the ground in late winter each year in somewhat the same way one would prune back a crepe myrtle (Lagerstroemia). Blooms on both new and old wood, so loss of top growth to winter weather or late winter pruning will not eliminate flowering for the growing season.
'Honeycomb' may be hardier to zone 5b in St. Louis.
Noteworthy Characteristics
Genus name honors the Reverend Adam Buddle (1660-1715), English botanist and vicar of Farmbridge in Essex.
The genus name is frequently listed today as Buddleia. However, Linnaeus named the genus Buddleja (pronounced with a silent “j”) which is still considered to be the proper spelling (first name survives) according to the International Code of Botanical Nomenclature.
‘Honeycomb’ is a yellow-flowered butterfly bush that typically grows in a single growing season to 5-7’ tall and 4-5’ wide with an upright-arching to spreading habit. If not pruned back each year, it will grow taller. It is a hybrid (B. davidii var. magnifica x B. globosa) that is noted for producing yellow flowers with orange eyes in globe-shaped panicles. In comparison to B. davidii forms, this hybrid produces stronger branching that is less likely to sprawl, but smaller flower panicles clumped at the stem ends rather than in long pyramidal clusters. Flowers are fragrant, and, as the common name suggests, very attractive to butterflies. Lance-shaped silvery leaves (to 8” long).
Problems
No serious insect or disease problems. Nematodes can be troublesome in the South.
Uses
Best grown in small groups or in massed plantings in borders, cottage gardens or butterfly gardens.