On the list of plants I can’t do without, butterfly bush (Buddleja davidii, Zone 6) is near the top. These borderline tender shrubs are best treated as perennials, and cut down each year to about six inches (15 cm). In cold winters, they most often died in my garden, to be replaced in spring with new plants. But the past several years, winters have been warmer, and the butterfly bushes have survived. The good news is that there are now several new cultivars of dwarf butterfly bush.
I started out growing dwarf Nanho Blue (‘Mongo’, syn. ‘Petite Indigo’), an airy plant with fragrant arching clusters of soft violet-blue flowers and silver-green foliage. It’s a real draw for butterflies of every kind, and also bumblebees and tiny non-stinging wasps. Then I added creamy yellow dwarf ‘Honeycomb’ (B. x weyeriana ‘Honeycomb’), a soft and graceful colour that goes with everything. There’s also ‘Royal Red’ (B. davidii ‘Royal Red’, 59 inches/150 cm), an intermediate size that can compete in a shrub border.
This season I’m looking for ‘Blue Chip’ (B. davidii ‘Blue Chip’), the first in the Lo & Behold series of miniature butterfly bushes, measuring just 24 inches (60 cm) tall and wide. Plants this size could be used for edging a walkway or filling in between roses, or even in a large container with strands of ivy spilling down the sides. ‘Blue Chip’ has deep blue-purple flowers that bloom from June to frost that don’t require deadheading, making it exceptionally low maintenance. White ‘Ice Chip’ and lavender ‘Lilac Chip’ are next in the series.
Butterfly bushes grow quickly, and full-size versions can reach five to six feet (1.5 to 1.8 m) in one summer. At that size, it can be an ungainly plant, and take up much space in a modest planting bed. The dwarf cultivars are mostly three to four feet (90 to 120 cm) tall and wide, and that reduced size might allow for more than one plant. Dwarf butterfly bushes bloom for eight weeks or longer if spent flowers are deadheaded, and they make good companions to ornamental grasses and tall summer annuals like zinnias.
They also bloom longer when regular irrigation is provided. Established plants will tolerate short periods of drought, but can’t stand to have roots in water. Be sure to select a site with good drainage.
One of the joys of butterfly bush is the menagerie it attracts. If watching (or photographing) butterflies and buzzing bees is your interest, a butterfly bush will draw their rapt attention and hold them still for the camera.