It's back! Yes, you can once again grow loosestrife and not be hounded by the eco-nazis. In fact, Lythrum alatum is native to all but 12 US states. Okay, it's not as pretty as the hybrids and when grown in a swamp, it's slightly more aggressive, but if you're out to clog up a waterway, it might as well be with a native plant. The 3.5' tall stems compose a bushy 3' wide clump. Starting in May and continuing most of the summer, the clumps are adorned with small lavender flowers on terminal spikes. As you can imagine, moist soils are preferred.