If you want it to form seed pods, don't cut off the spent blooms. We have to treat it as an annual here, so I harvest seed and start it in pots in the greenhouse in March. It also will self sow in the garden. It may be warm enough where you are for it to be perennial. I'm not sure. There are some really lovely daturas, double and triple purples and yellows. They are very easy to grow. Please note that all parts of the plant are poisonous. It is a sacred plant to several different religions and has been a witches herb for centuries.