Butterfly Bush, Butterfly-bush, or Summer Lilac

(Loganiaceae - Logania Family)

Form

• medium-sized to large-sized shrub
• maturing at about 8' tall by 8' wide or even larger (if never pruned) in its southern range, but often dying back close to the ground in most Winters in its northern range (and often achieving a 5' tall by 5' wide status by season's end)
• upright rounded (but very open) growth habit
• rapid growth rate

Culture

• full sun to partial sun
• performs best in full sun in moist, well-drained, fertile soils, but is very adaptable to poor soils, dry soils, and soils of various pH, and is tolerant of heat, drought, and high humidity
• propagated by seeds or rooted stem cuttings
• Logania Family, with few diseases or pests of ornamental significance
• abundantly available in container form
• in northern climates and even in many southern climates, it looks and performs best if pruned back hard in early Spring for rejuvenation and vigor (it blooms on new wood), and also to lightly shear the vigorous new growth in mid-June (before the initial flowers emerge), to promote a more dense and compact form at flowering, instead of the open and gangly growth habit that will be evident by season's end

Foliage

• emerging late in Spring and maturing to medium green, gray-green, or dark green (depending upon cultivar); glabrous above, but white-tomentose beneath
• leaves are opposite, ovate to lanceolate, serrated, with a short petiole and acuminate apex
• fall color is green and holding late, then either abscising or remaining as semi-persistent green or brown foliage into the Winter

Flowers

• purple, light blue, lavender, reddish-lavendar, pink, white, or golden-yellow miniature flowers with orange throats occur densely along a cylindrical to narrow pyramidal, often nodding inflorescence at each stem tip, generally about 6" to 10" long
• fragrant blooms occur heavily from July through August, and continue abundantly until frost if deadheading occurs (or sporadically if deadheading does not occur), and attracting many bees, butterflies, and hummingbirds

Fruits

• compound fruiting stalk of two-valved capsules is not ornamental, but is a good Winter identification feature
• best to dead-head the immature fruiting stalks throughout the Summer, to promote continuous flowering and prevent self-sowing

Twigs

• the several-sided, semi-woody stems are very pubescent, sparsely branched, off-white to light brown in color, and mature as brown branches

Trunk

• not applicable

ID Summary

• foliage emerges late and has a silvery-white underside below the gray green, medium-green, or dark green uppersides of the lanceolate opposite leaves, with white tomentose stems that are sparsely branched, herbaceous to semi-woody, and give rise to elongated, narrow-pyramidal, slightly drooping, long inflorescences that are fragrant, generally in the cooler color range (with orange centers to the miniature flowers), and bloom all Summer and in early Autumn, attracting many bees, hummingbirds, and butterflies

USAGE

Function

• specimen flowering shrub that doubles as a butterfly/hummingbird attractant, often found in group plantings in island beds, at foundations, or at borders

Texture

• medium-bold in foliage/flower and when bare
• open density in foliage/flower and when bare

Assets

• inflorescences are fragrant, attract many butterflies and hummingbirds, and occur from July until frost
• vigorous growth responds well to early Spring rejuvenation pruning
• flowering occurs on new wood (the current season's growth)
• tolerant of heat, humidity, drought, and average or poor soils

Liabilities

• dies nearly to the ground almost every Winter in its northern range, needing annual pruning to remove the dead wood
• marginally root-hardy in severe zone 5 Winters
• may self-sow in exposed soils, especially in its southern range

Habitat

• zones 5 to 9
• native to China

SELECTIONS

Alternates

• shrubs that flower anytime from mid-Summer through Autumn(Caryopteris x clandonensis, Clethra alnifolia, Hibiscus syriacus, Hydrangea paniculata, etc.)

Variants

• many cultivars and varieties are available and are being continuously introduced and withdrawn from commerce, based upon the color, size, and fragrance of the inflorescences, as well as the compactness of the mature shrubs
• the "Nanho Series" and the "Petite Series" are known for their compactness, generally advertised as being about 5' tall and 5' wide at maturity, and come in a range of the cooler floral colors

NOTES

Translation

• Buddleia is named after Reverend Adam Buddle of the 17th century.
• davidii is named after Armand David, who discovered the shrub in China.

Purpose

• Butterfly Bush is the best Summer-long flowering shrub that is noted for both its showy fragrant inflorescences and their subsequent wildlife attraction.

Summary

• Buddleia davidii is known as a profuse Summer-flowering shrub whose fragrant flowers attract many butterflies and hummingbirds.