I torture my P. gigantea outside in low humidity 40-60% in San Diego. Some are in full sun and hang on as long as they are kept wet, others are in shade. But they all grow very slowly.
Is this typical of the species?
(The sundew is a volunteer seedling...very cool! There's cat litter in there...not acidic in the least) I have capensis and even dichotoma growing in those now. I'm loving that.
My p. esseriana grew much faster when I kept those:
I have not tried a peat based medium for the gigantea yet though.