Has anyone had a problem with this plant spreading by seed? I got it at the swap from a wonderfully generous person that snuck it into my truck (-;

I'm planting it in a large plastic bucket in my bog garden, and think that's likely to keep it from becoming a problem, but I just wanted to be sure. I know it can spread by seed, but I'm hoping that won't be a major issue. After Equisetum hyemale (not a problem if completely contained), I'm more careful about aquatic plant invasiveness.