From Ground: First, water the giant blue cohosh to dampen the soil around its roots, making it easier to remove the plant with less root damage. Then, use a shovel or spade to dig a generous circumference around the plant to avoid cutting into the root system. Carefully slide the shovel beneath the root ball and lift the giant blue cohosh from its place.
From Pot: Gently grip the giant blue cohosh at its base and tip the pot sideways, supporting the plant as it slides out. If the plant is root-bound, you might need to tap the pot's edges or press on the sides to loosen the soil and roots before removal.
From Seedling Tray: Moisten the soil in the seedling tray to make the roots less likely to break during the process. Use a trowel or your fingers to gently tease out the individual seedling of giant blue cohosh, making sure to support the soil and root ball as you lift it out of the tray.