How do you over-winter geraniums as potted plants?
Carefully dig up each plant before the first fall frost and place in a large container. Water each plant thoroughly, then place the geraniums in a bright, sunny window or under artificial lighting. Geraniums prefer cool indoor temperatures. Daytime temperatures of 65 to 70 degrees Fahrenheit and slightly cooler night temperatures are ideal. During their stay indoors, water plants when the soil surface becomes dry. Geraniums are likely to become tall and lanky by late winter. In March, prune back the plants. Cut the geraniums back by one-half to two-thirds. The geraniums will begin to grow again within a few days and should develop into nice specimens by May.