KY Colonel,
I don't know if there if there are any kind of restrictions (harvest season wise) on blood root. None that I have ever heard of anyway. Perhaps someone else here will know more about that.
I used to dig some blood root and star root and yellow root while hunting seng but the price was so low on those that it just was not worth my time to mess with it. It can also be a bit too much like work digging a big patch of yellow root or blood root - where hunting seng is much more fun.
Here is a couple pics of some blood root I found growing along the bottom of a bluff last year. It had some good root on it.
It was late in the year and it was hot and dry at that point so it was a little stressed.
TNhunter