Phlox paniculata 'Katherine': bare root plant

Phlox paniculata, known in English as "garden phlox", "fall phlox", or "summer phlox", and in French as phlox paniculée, is a perennial native to eastern and central United States. It bears clusters of showy five-petalled flowers in shades of pink, purple, or white. This cultivar will have lavender flowers with white eyes.

Garden phlox looks similar to dame's rocket (Hesperis matronalis, julienne des dames). You can distinguish the two by counting petals: phlox has five petals, dame's rocket has four. It's important to be able to distinguish them because dame's rocket is seriously invasive here in southern Ontario according to the Invasive Exotic Species Ranking for Southern Ontario (PDF). Since dame's rocket is considered "a threat to natural areas wherever they occur because they can reproduce by means that allow them to move long distances," I hope that other Toronto gardeners will join me in growing the equally pretty but non-invasive garden phlox instead.