From Ground: Water the french flax plant to dampen the soil which will make the roots easier to remove. Use a garden spade to dig a wide perimeter around the plant, being careful to preserve the root ball. Pry underneath the root ball gently to lift the plant out of the soil.
From Pot: Water the french flax plant before starting to ease the roots. Turn the pot sideways and gently tap the sides and bottom to loosen the soil. Grasp the plant at the base and apply a gentle pull; you can also press on the bottom of the pot to help ease the plant out.
From Seedling Tray: Water the soil first to minimize root disturbance. Use a trowel or a fork to gently pry the seedling out. Hold the seedling by the leaves, rather than the stem, to prevent damage.