[Ifurita]

I don't actively cultivate live sphagnum for use, but I do have several pots of it. From my experience, good light is a yes, but there is actually an optimum humidity level, beyond which the sphagnum will grow long and stringy instead...which is not really that healthy. Now temps are NOT necessary if you get a nice friendly heat resistant strain of the stuff. Most of my sphagnum grows outdoors and grows faster than the stuff which grows in my room and gets nice cooling. It may take a while to establish from a single head, but once it gets going, its pretty okay. For me I just chuck a head onto either the dead sphagnum or peat, either way works decent.