Fill the new container halfway with potting soil. Use a container that comes with drainage holes in the bottom and a detachable tray.
Remove the geranium from the original pot by turning the pot on its side and gently pulling the plant out by the base. Insert a hand spade between the soil and the side of the pot until it comes free.
Loosen the root ball with your hands by squeezing it to remove some of the old soil. Lower the plant into the new pot. Backfill the pot with potting soil until the geranium is planted at the same level it was in the original pot.
Water until the soil settles. Apply a flower fertilizer to the soil according to the package directions. Repeat the application once a month.