Cut the geranium plant back to half of its size in early autumn, before the first freeze of the season. Remove any brown or yellow leaves.
Fill a planting container a quarter to a third full with commercial potting soil. Be sure the container is clean and has bottom drainage holes.
Dig up the plant with a shovel or garden fork. Place the plant in a container at the same depth it was planted in the soil. Fill in around the plant with potting soil. Tamp the soil down lightly around the roots.
Water the geranium thoroughly after planting and allow excess water to drain through the bottom of the container. After that time, water the plant when the soil feels slightly dry to the touch. Never allow the plant to stand in water and discard any water that remains in the drainage saucer.
Place the plant indoors where temperatures will be constantly cool, but not freezing. The geranium should be exposed to bright, indirect light.
Pinch the tips of the stems back once or twice during the winter months to promote healthy, bushy growth and prevent the plant from growing long and leggy.
Plant the geranium outdoors after all danger of frost has passed in spring. Fertilize the plant lightly with a liquid fertilizer for blooming plants.