From Ground: Begin by watering the swamp sunflower plant and surrounding soil to dampen it. This makes digging easier and reduces the risk of root damage. Using your shovel or spade, dig a wide trench around the plant, ensuring to keep the root ball intact. Work the spade under the root ball and gently lift the plant (still intact with the soil around its roots) from the ground.
From Pot: The swamp sunflower plant in a pot may be easier to remove. First, water the plant well. Then, turn the pot sideways while holding your hand on the soil with the plant's stem between your fingers. Gently pull the pot off while keeping the plant and the root ball intact in your hand.
From Seedling Tray: For a seedling in a tray, water the tray to moisten the soil around the swamp sunflower plant. Use a trowel or a spoon to scoop the plant, making sure to lift the plant with enough soil to keep the roots covered. Do this carefully to avoid breaking roots and stem.