Butterfly Bush (Buddleia davidii) – Originating from China, Butterfly Bush is a delicious, perennial shrub known for it’s long plumes. The plumes feature a cascade of tiny, nectar rich flowers that attracts and provides food only, to adult butterflies, bees, hummingbirds and and other beneficial insects. The flowers colors can range from shades of blues, violet and purple but are generally white, pink and red.
Buddlelia is fast growing, deer resistant and low maintenance. It can grow to reach heights of 6 to 8 feet. Buddlelia requires full sun to reach its optimum flowering potential. It also requires well draining, average to slightly acidic soil. It does not, however, like excessive wet soil. Once the plants are established, they become drought tolerant and require only occasional watering unless subjected to extreme heat. Aggressive pruning during late fall only is recommended in mild climates. In cold climates, Buddlelia should be cut close to the ground (be forewarned the stalks are woody and tough) and mulched heavily until spring. Buddlelia generally flowers the first year, when started early (blooms from summer to autumn).
The bad news: Buddlelia is becoming a invasive species in many climates; in particular the Pacific Northwest (has been banned in Oregon) and most of the eastern seaboard. Because seeds are easily dispersed naturally by weather and birds, deadheading spent plumes is recommended. The good news is non-invasive varieties have been cultivated and are perfect for perennial gardens and containers.
Non-Invasive Buddelelia Varieties:
Blue Chip’ Lo & Behold® Buddlelia – (also known as summer lilac in Oregon and Washington) – 24 to 30 inches – Flower Color (s) blue – purple
Inspired Pink – 48 to 72 inches – Flower Color (s) pink
Asian Moon – 5 to 7 feet – Flower Color (s) blue – purple
Lo-Behold Purple Haze – 24-36 inches – low spreading and perfect for ground cover, mass or foundation planting – Flower Color (s) purple
Butterfly Bush Flutterby Grande Blueberry Cobbler – 4 to 6 feet – Flower Color (s) blue, yellow-orange
Butterfly Bush Flutterby Grande Peach Cobbler – 4 to 6 feet – Flower Color (s) pink-orange
Flutterby Grande™ Sweet Marmalade Butterfly Bush (Summer Lilac) – 4 to 6 feet – Flower Color (s) – orange
Flutterby Grande™ Tangerine Dream Butterfly Bush – 4 to 6 feet – Flower Color (s) yellow-orange
Flutterby Grande™ Vanilla Butterfly Bush – 4 to 6 feet – Flower Color (s) white
Flutterby Petite® Snow White Butterfly Bush – 24 to 30 inches – Flower Color (s) white
Flutterby™ Pink Nectar Bush – 24 to 30 inches – Flower Color (s) pink
Additional Resources:
https://www.provenwinners.com/search/content/buddleia?f[0]=bundle%3Aplant_identity
https://plants.monrovia.com/search?w=buddleia
https://www.americanmeadows.com/search/go?w=buddleia
Garden Variety 
I have a Buddleia Buzz (a dwarf variety) which I planted two years ago and the butterflies and I love it!
I am sure they love you for planting it. 🙂
Are the non invasive buddleia sterile? If so, how does this affect the insects that come to them for sustenance?
Most non-invasive varieties are 98% sterile unless they are planted near an invasive Buddleia (cross pollination can create non-sterile flowers). The insects have no problem enjoying both non-invasive or invasive Buddleia.
Oh my! that is what happened with the ‘non invasive’ pampas grass. They were all female, so made no pollen. However, they were pollinated by the very invasive Cortaderia jubata.
Useful to know about non invasive, have been thinking about how quick could get a big buddlea plant to fill a space but heard they are causing a nightmare spreading onto UK railways.