I just bought a Firebush in hopes of attracting hummingbirds. I do not want to put it in the ground but want it on the patio. Although I know they are heat tolerate, I am worried about the heat on the roots in a planter (as well as the cold in winter). Is there anything special/different I need to do to keep a"potted" Firebush thriving? I am not an experienced gardener so please talk to me like I am in kindergarten! Thanks!