Very few annual plants overwinter successfully in the home. Geraniums allow gardeners to bring a little bit of summer into the home before the first sign of frost. Gardeners can overwinter the plant in the home and capitalize on the geranium's beautiful foliage during the cold winter months. Take advantage of this plant's versatility and save your geraniums to use the following year.
Remove the geranium from the garden or flower pot using the trowel. Shake off excess dirt from the roots of the plant or rinse lightly with a garden hose.
Examine the leaves of the geranium for damage or the presence of insects. Leaf discoloration indicates the presence of bacterial disease and should be discarded to limit exposure for other indoor plants. Rinse the entire plant with a garden hose sprayer to remove insects from foliage and roots.
Fill a clean pot half full with new potting soil. Scoop out a small hole to accommodate the geranium roots and position the plant in the center of the pot. Fill in around the roots with loose potting soil and firm lightly with fingertips to secure the plant.
Place the pot into a drainage tray and water the geranium around the base of the plant. Soil should be evenly moist and not soggy to the touch.
Prune back all foliage to 6 inches. Make cuts above healthy leaves at a 90-degree angle. Remove any dead foliage using pruning shears and clip back all flower stems. The final groomed plant should resemble a small, bushy geranium.
Place the plant pot in bright indirect light for the winter months in a location experiencing 70-degree F daytime temperatures. Apply water-soluble fertilizer once a month beginning one week after transplant. Geraniums won't flower unless the plant receives at least 4 hours of direct sunlight each day. Make sure the plant doesn't dry out but allow the soil to dry between watering.
Monitor the plant weekly to check for legginess in the form of extended stems without foliage. Pinch back this leggy growth using pruning shears to promote new growth.