From Ground: Start by watering the spreading phlox plant area to soften the soil. Use a spade to dig a wide trench around the plant, careful to keep the root ball intact. Once done, carefully work the spade under the plant to lift it from the soil.
From Pot: If the spreading phlox plant is currently in a pot, water it generously a few hours before transplanting. This will help the roots hold onto the soil. After it has been watered, tilt the pot sideways and gently open the container to remove the plant, making sure to keep the root ball intact.
From Seedling Tray: If the spreading phlox is in a seedling tray, make sure it is well watered before moving it. Use a trowel to gently lift the spreading phlox plant from the seedling tray. Hold the plant from its base and gently lift it, being careful not to damage the roots.