I have two "Flower Power" Buddleia's to attract pollinators to my vegetable patch. I cannot guarantee they are 100% sterile but they haven't propagated yet and seem to be the choice for non-invasive Buddleia's here in Europe.
The only thing I can say is they are among the most effective Buddleia's I have seen when it comes at attracting pollinators... the amount of butterflies, bumblebees etc they attract can get scary.
