I was all ready for witchery, making an entire room and everything to compensate, when i tried to place down some vanilla saplings, long story short they don't stay. I don't know if this is something to do with it being the last millenium or if it is something else
Chugga is right. Try placing torches or glowstone nearby. Because it's so dark you need a light source.
i used glowstone illuminators and i turned them on[DOUBLEPOST=1440087081][/DOUBLEPOST]it didnt work even then