There is a research paper by Dr. Marla McIntosh of the University of Maryland, it's very technical, but part of the research is attempting to grow ginseng on the eastern shore of MD. It is a very long paper, so you might want to just skip to the conclusions. To sum it up they had some success with seeds but much better success with rootlets. Their results about the use of lime vs gypsum were also interesting. The area they picked may be similar to your conditions. Here is the Link, it is the second bullet on the page \"
Cultural Practices Affecting the Profitable Production of Ginseng in Different Physiographic Regions of Maryland Forests Contact: Dr. Marla McIntosh\"
http://agroecol.umd.edu/Research/forestry1.cfm
The direct link to the PDF file is:
http://agroecol.umd.edu/files/M.%20McIntosh%20Ginseng.pdf
You should also get a copy of Scott Persons book on Growing Ginseng. He mentions Andy Hankins, in the book, who is part of the Virginia Cooperative Extension. Andy encourages people to try to grow Ginseng in suburban areas of Virginia. I believe he has used some grant funding to send seed to people in different areas of VA.
I am going to give it a try, I just got some seed in the ground this past weekend. I am in Manassas VA. Not Coastal plain, but not really mountains either.
Hope you give it a try.