Note: Poke has poisonous parts and if gathered and prepared incorrectly can be poisonous. In no way do I recommend that you eat poke. Below is only my own personal association with this plant.
Once again it's time to perform the Holy Ritual to remember my hero Euell Gibbons. I spotted the patch of Poke Salad last year and remembered where it was. I snuck past all the No Trespassing signs and gathered one handful of young stems & greens of one foot plants. The plant in the picture is poke, but the plant is much too old to eat. If you see plants like this, remember where they are and come around next Spring when the plants have just sprouted. A handfull is plenty for one person. Poke doesn't cook down as much as other greens. I open the Holy Book ( Euell Gibbons' "Stalking The Wild Asparagus" , 1965 fourth printing ) to page 176 and read the cooking instructions, I bring to a boil a gallon of tap water and then throw the plants in. This is important. If you bring the water to a boil with the plants in there, it drives the bitterness in. I parboil the greens with a rolling boil for 10 minutes. I then carefully pour this water out catching the greens in a strainer, return the greens to the pot and then pour enough fresh boiling water in to almost cover the greens. Then add one strip of bacon and a tablespoon of salt, bring back to a boil, cover, then simmer for 20 minutes. Pick out the two pine straws that always find their way into the pot, and I have one of the finest cooked vegetables you can find in the wild.
If you want to grow poke from seeds see Mother Earth News.