Here they are native and we have them all over the garden and that is 25 feet of pure sand, often under huge pine trees, so to say that these are easy is an understatement, but I'd agree with Carol about them needing a bit of a chill period. As I understand things the pips should be a bit thick to be of blooming size. If they are thin and pointy they will only develop leaves the first year. However yours have already started to grow some, so would perhaps look a bit thin anyway.
