I grow it as a weed because it likes to be kept above 50°F and is very invasive in the Azores. Plenty of water to get it going. It will take dappled shade - I pull out a lot of new plants in my woods every year. It doesn't always flower on every stalk, but dies back in winter and sends up a new stalk(s) every year. You can cut and toss the old parts every couple of years. The pot needs to be deep as the roots are long, and I get stalks that are 4-6" tall. After it flowers, let the seeds develop - it is just as interesting as the flowers.

some of the nicest things can become weeds in different climates.... in u.k. the cold wet winters usually see most things off but not seeds. we have problems with Himalayan balsam being a very beautiful but invasive weed too