Philodendron Melanochrysum growth rate.
I have purchased a mature specimen of a Philo. Melaochrysum but since i have had it, it doesnt seem to be happy and has stopped growing. I have put it in a warm heated greenhouse with numerous other tender aroids such as Anthuriums, Alocasias and about a dozen other different Philodendrons and everything else is growing great with big leaves and rapid lush growth so much that the greenhouse is almost completely over-grown with tropical aroids every since i got the heat/light/humidity right except for this Melanochrysum that just sits on the bench doing nothing. Is it a particularly difficult Philo to grow or what, any tips please.