Grow your snapdragons in an area that receives full sun or light shade for the best flowering results. They also like soil that drains quickly and contains compost or peat moss. Also, limit the amount of fertilizer you give your snapdragon. The nitrogen in many plant foods causes excessive foliage growth at the expense of flowers.
Deadhead spent blossoms when they appear. Cut spent flowers at their base at an angle that follows the stem. Because this plant is a prolific bloomer, you might need to search through your plant to find the faded flowers.
Cut back tall plants to as much as half their height. Cut parallel to the ground just above a leaf or flower node and use the tops in a floral arrangement. New flowering stems will grow from nodes just below the cut area.