I do happen to have a N. mirabilis planted in the ground, more or less
as an experiment. My other outdoor Neps. and Sarrs. are in pots in
water trays. The snail catchers had the advantage of being closer to
the ground, and in the Neps. case, had a trailing vine dropping
pitchers into the grass growing up beside the house.
I have a N. rafflesiana but I haven't moved it outside yet. On the
positive side, humidity and temps are pretty good here but we still have
occassional winter cold. My Neps are either brought inside or well
covered. The planted N. mirabilis stopped growing but was not too
damaged but another large plant is only now recovering. And even the
humidity here is not enough for some picky species. I don't know yet
how picky my particular N. raff. is.
Tom in Fl.
PS. I just saw another zone designation map which roughly characterized my area
as having occassional freezes, and the area just north in Florida as expecting
at least an annual hard freeze. That about sums it up.