Whether geraniums are annual or perennial flowers depends upon your growing region. Geraniums are a tender perennial plant in USDA zones 8 through 10, and they are annual flowers in colder regions. If you live in Texas, the southern half of the state is suitable for wintering geraniums outdoors as long as you take care to protect the plants during any occasional frosts. Northern Texas gardeners should bring geraniums indoors to keep them growing over the winter.
Geranium Care in USDA Zones 6 and 7
Dig up geraniums growing in the soil prior to autumn frosts. Use the trowel to loosen the geraniums from the soil, taking care not to disturb the roots as you remove the plants from the soil.
Fill the planting containers approximately half full with potting soil. Use one planting container for each geranium you dig up.
Transfer the geraniums to the planting containers and fill additional potting soil in and around the plants to finish repotting the geraniums.
Water the transplanted geraniums generously immediately after you plant them.
Place the geraniums in a warmer location that receives some sunlight. An enclosed porch or indoors in a sunny window would be ideal.
Water the geraniums throughout the winter when the soil becomes dry, watering only enough to moisten the soil again.
Transplant the geraniums back outside the following spring.
Geranium Care in USDA Zones 8 through 10
Move geraniums growing in containers to a sheltered location if you expect freezing weather. Place the geraniums temporarily in a garage, shed or basement while the temperatures are below freezing. When the weather warms again, move them back to their regular growing location.
Cover geraniums growing in the ground with a frost blanket prior to freezing weather. Cover the geraniums the evening before the freezing weather occurs and uncover them again the following morning when the weather climbs back up above freezing again. Do not leave the frost blanket on the geraniums throughout the day, but rather replace the frost blanket again the following evening if you expect another overnight frost.
Provide water for the geraniums throughout the winter months to keep them vibrant and healthy. Provide water when the soil dries to moisten it again.
Deadhead the geraniums to remove spent blossoms. Clip the stems with spent blossoms back to the point just above the first leaf node.