I thought P. mad was hard to grow until I stopped trying to grow it and let it do it's thing. If I keep the bugs away it loves to grow. Now I have so many I don't know what to do with them all. I keep them in cool temps and in FULL sun and they all seam to thrive just fine. I took me a few years to just let go and let them do there thing. But now I am so happy. I keep some dry and some on the wet side. I know wanna says that they do not like it hot but I don't know if I agree. They are vary prone to Fungus so I don't move them around and do not touch them. This could be something that keep the ones I have alive. I have grown them in the LOW 30's and they do fine also. I do have some that are not growing well and they are ones that I find where stressed by bugs attacking them. But the Spore Grown ones I have all are doing so well. Keep growing them I'd try getting like 5-10 and keep them apart form each other Good air is a must.
If you can grow them outside. Good luck with this species... I love P. madagascariense........