Plant your phlox in well-drained soil. Check the label on your plant; some phlox thrive in full sun while others prefer shade.
Till the soil 12 to 15 inches deep while adding 2 to 4 inches of compost. This will assist with moisture retention and drainage.
Dig a hole for the plant that is twice the diameter of the root ball and as deep as the container. Space the holes 1 to 2 feet apart.
Turn the container upside down and tap on the sides and bottom to remove the plant.
Place the plant in the hole, making sure the top of the root ball is at the soil surface. Fill in around the roots with soil and gently pack it.
Sprinkle a starter fertilizer around the base of the plant and water thoroughly.
Apply a 10-10-10 fertilizer each month of the growing season. Water the plants immediately after application to assist with absorption.
Soak the plants deeply once a week if rainfall is less than 1 inch a week.
Cut old flower stems as the color fades; this will promote new blooms. Cut the stems to 2 inches after fall's killing frost.
Divide tall varieties of garden phlox every two to three years in the spring to control disease associated with dense growth.