Hugh is dead on. Refrigeration seemingly is one of the major issues with delayed germination, and another is drought (less than ample rain at the right times).
Of course, also consider that ginseng is a perennial plant and perennial plants in general have very complex dormancies. Sometimes they don't come up the first year apparently just because they don't want to.
Let me give you a personal experience. Two years ago I moved to this place. It was late in the year by the time I got my new beds in for the seedlings I sell. Viability in the seed was lower than normal (75% and 80% in two lots...normally around 95%), so I planted especially thickly. Well, I have to say they all came up. ...at least it seemed that way.
Because the babies were as thick as grass, when we dug we created clear cuts of sorts all the way across the middle of the beds to create a sort of disease break. Well, imagine my surprise when I looked at those beds this spring and the clear areas had seedlings coming up in them as if I had intentional replanted them last fall.
Clearly there was nothing wrong with the seed or its handling, or the weather conditions last spring. Yet, a percentage of the seed delayed germination until this spring.
So in the end, don't get discouraged. You might be pleasantly surprised next spring. All part of making ginseng a wonderfully intriguing plant.