Above is the mature plants and a good healthy plant can grow as tall as fourteen feet. When it is this mature, nothing is edible, not the berries, not the stalk nor the leaves and especially not the root!!!
This is the stage when it is best picked for food.
Although the birds do eat the berries and thus,
spread the growth of Poke,
it not recommended for humans.
So why and how do we eat a plant that is so poison??? The why is because it is so darn good, simple as that.
The how is also simple, wash it, boil it and change the water three times, is the old rule. The younger it is, the fewer water changes required. You may pick dock, dandelion, spring lettuce and other wild plants to add a change of flavor. They all serve the same purpose combined. They are the first dish of spring and they serve as a "spring tonic". The young stalks can also be peeled and fried like okra or simply include them, cooked, in your pot of greens. Never eat it raw.
You know you did not change the water enough, if the inside of your mouth peels. Just a minor discomfort, not deadly.
After the water is drained during the last boil, put greens in skillet with seasoning (traditionally, bacon drippings and salt) and cook the liquids out. Many people like eggs scrambled within their greens but I prefer mine straight up.
I have eaten poke salad, cooked, every spring of my life and find myself hungry for it as the shoots peek out of the ground.
May sound kinda strange to eat a plant that could make you sick, but I think it's good to know where the food is if the grocery stores close.