Early spring is when you should plant them in the ground. Make sure you keep them either labeled or separated when you do...it's not hard to lose track of which one was what... Mine start growing in march, but they are fairly established. Young plants and rhizomes you need to take care of, because frost can do serious damage to them. If you are out of the frosting period where you live, then you would probably be safe in getting them in the ground. If you don't mind me asking...what are they going to be growing up? Trellis? Flag pole with teepee setup?