Roachy,
I would say that the ideal depth will vary by location and soil type and the type of mulch used.
If you are doing wild-simulated plantings.
In the average woods soil and considering you are mulching with the leaf litter that naturally occurs in good ginseng woods (not too much oak, but more maple, poplar, softer easier to break down leaves)...
I would suggest the seeds be covered with 1/2\" to 1\" of top soil (including that composted leaf layer that might be considered part of the top soil) and then cover with leaves (loose a couple inches deep).
I played around some with different planting methods last fall.
I did some with standard rake and scatter method that I would say got the seeds covered around 1/4 inch deep in leaf mulch (mostly) then loose leaves.
I had excellent germination and they were looking fine the first week in June.
When I checked them agian the first week in August they were all gone.
We had basically no rain from July 1 until Sept 4 this year and some extreme heat during that time.
The seeds that I planted using regular rake and scatter germinated great and did fine thru June, but the extreme heat and dry later in the year, the tops died out. I am not sure if they will come back next spring or not. I hope they do.
I did other plantings using double rake and scatter method. I would say that on average those seeds got covered with 1/2 to as much as 3/4 inch of soil.
They germinated fine, and they were still living the first week in August when I checked them.
I did another planting using Hankins Method, where I actually dug furrows about 1\" deep and coverd the seeds with that much soil, then leaves. They sprouted fine too and they were doing OK in August this year.
Germination wise - I could not really tell any difference in the ones that were planted 1/4\" deep, 1/2\" dep or 1\" deep. They all germinated fine.
But the ones that were planted only 1/4\" deep did not survive a brutal hot and dry July month here in Middle TN.
I plan to use mostly double rake and scatter method from now on - unless I figure out something better this planting season.
PS - I have seen at least one website (Ozark Mountain best I remember) where they recomnmend planting 2\" deep. I have never tried planting them that deep myself. If you had really loose, loam type soil that would probably work OK but in heavy clay it may not.
I have a couple of vids on my youtube channel showing how I did the double rake and scatter method, and some showing 3 leafers up this spring. Also several showing some genseng hunting.
www.youtube.com/yttnhunter
Good Luck to you this year !
TNhunter
