Battle of the Butterfly Bush
Few garden plants are truly “controversial”, but Buddleia is.
A dwarf, sterile, and exceptionally handsome Buddleia.
A native of China, Buddleia davidii is a showy, vigorous species of the beloved butterfly bush. The same ample bloomheads that make this species attractive also produce an abundance of seeds (over 100,000!), which lets them swiftly colonize open spaces. Their fantastic adaptability to poor, dry soils also makes them very capable of taking over wild areas. Since their introduction they have naturalized in several parts of the UK, North America, New Zealand, and Australia. The shrubs are so robust and determined to grow that they have even been spotted growing in cracks in the concrete!
Many conservationists have been alarmed by the prolific nature of this foreign species and have taken action against it. B. davidii is listed as a weedy or invasive plant in 30 states. It seems to especially thrive in the Pacific Northwest. In Oregon and Washington, B. davidii is banned for sale out of concerns that it might overrun the landscape and inhibit natural reforestation.
Fans of the species fail to see the problem with having an abundance of beautiful butterfly-feeding shrubs around. Butterflies seem just as content to feed from this Chinese species as from native species, and anything to help the butterfly populations is good.
Non-Invasive Alternatives
Bans, restrictions, and general bad press have had a strong negative impact on Buddleia breeders, but recently they’ve found a solution: sterile cultivars. Interspecific cultivars like ‘Miss Molly’, ‘Miss Ruby’, and ‘Miss Violet’ and several sterile cultivars (producing less than 2% viable seed) like ‘Asian Moon’, ‘Inspired Pink’, The Flutterby™ Series, and the Lo & Behold® Series have all been recently exempted from this rule and are now legal to sell in Oregon. These sterile cultivars must be distinguished, however, by being sold under a different name, like ‘Summer Lilac’ or ‘Orange Eye’.
No matter where you live in the country, we encourage you to choose non-invasive Buddleia cultivars just to be sure you aren’t inadvertently introducing a problem into the ecosystem. Just look for “Summer Lilac”!
Resources
http://www.oregon.gov/ODA/programs/NurseryChristmasTree/Pages/ButterflyBush.aspx
http://www.chicagobotanic.org/sites/default/files/pdf/plantinfo/buddleja2015.pdf