My favorite place of all to look into is a north facing slope/holler/ridge where their are large Maple trees and or alot of maples.
My 2nd favorite spot to look is in an area that has alot of vines droping down with maidenhair fern and/or solomon's seal and most of the time the soil will be blacker in color when you find them vines and the fern together,very,very good soil.
I find it where their is Black coash,blood root,golden seal,stone root and even though these dont seem to be as sure as those above I still like to see them often in a mountian especialy if their is not much Maple,or madienhair fern around the area.
But if you ever find a northern side of a mountian with alot of old maples around that has not been found by someone or dug by someone in a good while.Just get ready to thank the good Lord for what you are about to exsperience :o) then post the pictures and I`ll be happy for you to
I agree with Billy, always look for the North facing slope. Its amazing how the ground cover changes when that hill starts to bend around and face north. Next biggest thing I look for is any type of cohosh, especially black (we call it rattleweed). Just found a bunch around some cohosh and ferns. Jack in the pulpits are good indicators to but sometimes as hard to find around here as seng. I always look for fallen timber where some sun is getting in- always seem to grow bigger there.
I agree with billy trees and the facing of the slope is the main key. If u find a north facing with poplars and maples they will be seng and all of the other companion plants and especially if like Billy said if no one has been there get ready for a good time. U don't find them that often.