Colorful spring or summer flowers, sweet fragrance, attractiveness to butterflies, and easy care make these shrubs extremely popular. The vast majority sold are selections of B. davidii, but many other species are highly ornamental and deserve their fair share of attention. Most types prefer full sun and fertile, moist, well-drained soil. Not browsed by deer. Removing spent flowers extends bloom.
B. alternifolia. FOUNTAIN BUTTERFLY BUSH. Deciduous. Zones US, MS, LS, CS; USDA 6-9. Native to China. Shrub can reach 12 ft. or taller and equally as wide, with arching, willowlike branches rather thinly clothed with 1- to 4-in.-long leaves, dark dullish green above, gray and hairy beneath. Blooms in spring from the previous year's growth; produces profuse small clusters of mildly fragrant, lilac purple flowers that create sweeping wands of color. Tolerates many soils; does very well in poor, dry gravel. Prune after bloom: remove some of oldest wood down to within a few inches of ground. Or train up into small single- or multiple-trunked tree. So trained, it somewhat resembles a small weeping willow. 'Argentea' has silvery gray foliage.
B. davidii. ORANGE-EYE BUTTERFLY BUSH, SUMMER LILAC. Deciduous or semievergreen. Zones US, MS, LS, CS; USDA 6-9. Native to China, Japan. Fast, rank growth each spring and summer to 5, 6, or even 10 ft. tall and wide. Leaves tapering, 412 in. long, dark green above, white and felted beneath. In midsummer, branch ends adorned with small, fragrant flowers in dense, arching, spikelike, slender clusters from 6 to 12 in. or longer. This species and its selections require little more than good drainage and enough water to maintain growth. Cut back plants heavily (nearly to the ground) in late winter to early spring to promote strong new growth for good flowering. In Upper South (USDA 6), plants may freeze to the ground but will regrow each year from the roots. This species is considered invasive in much of the Upper South; gardeners there should consider selections with reduced seed production.
'Black Knight'. Darkest flowers, very deep purple, in 4- to 6-in. spikes. Small leaves. Grows to 67 ft.
'Blue Chip'. Dwarf plant grows just 3 ft. tall and wide, with dark green to gray-green leaves and blue-purple flowers. Does not sucker and produces few if any seeds. Part of Lo & Behold series.
'Bonnie'. Attractive gray-green foliage and very fragrant, light lavender blooms in spikes 812 in. long. To 10 ft. tall and wide.
'Charming'. Blue-green leaves. Lots of large, lavender-pink flowers in spikes 68 in. long. Grows 68 ft. tall and wide.
'Dartmoor'. Strongly fragrant, purple flowers in 6- to 8-in., branching spikes with a very full look. To 6-10 ft.
'Ellen's Blue'. Long bloom season, with deep, intense violet-blue flowers in 6- to 10-in. spikes. Silvery green leaves. Grows just 4 ft. tall and wide.
'Empire Blue'. Violet-blue flowers in spikes to 1 ft. long. Silvery green foliage. Vigorous, upright growth to 1012 ft.
'Harlequin'. Cream variegation on leaves. Reddish purple flowers in 6- to 8-in. spikes. Slower growing than most, and leaves may revert to green. To 78 ft.
'Ice Chip'. Compact grower, just 2 ft. tall and twice as wide. White flowers. Virtually seedless. Part of Lo & Behold series.
'Lilac Chip'. Low growing form, at just 1 ft. tall; spreads to at least 2 ft. wide. Lilac-colored flowers. Very low seed set. Part of Lo & Behold series.
'Miss Ruby'. To 56 ft. tall and wide. Resembles 'Pink Delight' but with more compact growth and brighter pink flowers. Choice.
Nanho series. Plants grow to 46 ft. tall and wide, with small, narrow, silvery leaves. 'Nanho Alba' is dense, with white flowers in 8- to 10-in. spikes. 'Nanho Blue' offers profuse blue blooms in 4- to 6-in. spikes. 'Nanho Purple' has dark violet flowers in 4- to 6-in. spikes.
'Opera'. Purple-red spikes are 1012 in. long. Bushy plant to 57 ft.
'Orchid Beauty'. Clusters of lavender flowers up to 20 in. long. To 58 ft.
'Pink Delight'. Spikes of clear pink flowers to 1 ft. long. Silvery foliage. To 68 ft. Considered by some to be the best pink form.
'Potters Purple'. Violet flower spikes to 10 in. long. Vigorous, upright plant to 7 ft. tall. May be the best purple buddleia.
'Purple Haze'. Low, spreading growth to 23 ft. tall and 46 ft. wide, with dark green leaves. Medium purple blooms on arching horizontal branches. Produces no seeds.
'Purple Prince'. Very fragrant, violet flowers in spikes 614 in. long. Upright growth to 6 ft.
'White Profusion'. The best white selection. To 68 ft., with many 8- to 12-in. flower spikes produced over a long period. A magnet for butterflies.
B. lindleyana. WEEPING MARY. Semievergreen. Zones MS, LS, CS; USDA 7-9. Native to China but sometimes found growing wild in the southeastern U.S. Graceful, open growth to 612 ft. tall, not quite as wide. Purplish violet flowers appear in late summer and fall, carried in nodding clusters that may reach 2 ft. long. Deep green, semiglossy foliage; cinnamon-colored, shedding bark. Try removing lower limbs to allow for understory plantings. Blooms on new growth; prune as for B. davidii.
B. 'Lochinch'. Deciduous. Zones US, MS, LS, CS; USDA 6-9. A hybrid between B. davidii and another species. To 56 ft. tall. Displays woolly white new growth and branching, foot-long clusters of intensely fragrant, lilac blossoms with an orange eye. Produces summer flowers on current year's growth, so prune as for B. davidii. Excellent flowers and foliage.
B. x pikei 'Hever' ('Hever Castle'). Deciduous. Zones US, MS, LS, CS; USDA 6-9. Hybrid between B. alternifolia and a Himalayan species. Resembles a smaller B. alternifolia, with fragrant, orange-centered lilac flowers in mid- to late spring. Gray-green leaves. Prune as for B. alternifolia. Seedless.
B. x weyeriana. Deciduous. Zones MS, LS, CS; USDA 7-9. Hybrid between B. davidii and a species from Chile. Produces arching, leafy shoots set with roundish clusters of yellow-orange flowers. To 810 ft. tall and wide. Blooms on old wood, so cut back after flowering as for B. alternifolia. (In coldest part of range, however, it freezes to the ground and so blooms on new wood.) 'Honeycomb' is choice, with golden yellow flowers. 'Sungold' has dense clusters of dark orange-yellow flowers.