Stephen, when it comes to planting ginseng seed, it is always recommeded doing it after the rain or when the soil contains enough moist. In general, ginseng hates wetness, yet loves moisture. On the one hand it does poorly in heavy, soggy soils especially bottom lands. The roots will rot if planted in low-lying areas. On the other hand, ginseng requires at least 20 inches of annual rainfall. Lack of available soil moisture greatly reduces germination, root growth, and seed production.
FYI, the best soils are humus rich sandy roams located on north or south facing slopes with sufficient moisture even during dry spells. Hope this helps and good luck with your ginseng!
As long as you didn't cover them with alot of oak leaves, as long as they don't dry out, and as long as you didn't sow them too thick you should have about 50% of them come up for you, maybe a little more. In about three years you should have a good idea of how many plants you will have available to dig from that planting in the future. The die-off will be higher with thicker planting methods. I wouldn't plant them any thicker than about 4 seeds per square inch.