Geraniums grow slowly when planted from seed, so they should be started indoors in the middle of winter. If started indoors, geranium seeds will have plenty of time to germinate and grow; they will be ready to flower just in time for summer. Shallow pots with good drainage, light, a good potting mix, and a dash of water are all that geranium seeds need to begin growing. Once planted, geraniums don't require complex or specialized care to thrive.
Good drainage is essential for geranium seedlings; geranium seeds are susceptible to a variety of fungi that can damage or destroy freshly sprouted seedlings. Almost any kind of shallow container will work as a geranium seed starter, including seed trays, egg cartons, paper cups, or recycled food containers. Using a sharp implement to poke holes in the bottom of a container is a good way to promote drainage when planting geranium seeds.
A commercial potting medium or germination mixture will yield the best results when planting geranium seeds. To plant the seeds, the containers should be filled almost to the top with the potting mixture, then watered. The pots should be allowed to drain for at least an hour, and then geranium seeds can be sprinkled on top. Cover the geranium seeds with a thin layer of soil; then lightly water.
Once planted, the seed containers should be placed indoors in a warm area and allowed to grow. Covering the seed pots with plastic wrap or a glass dome may help speed germination. The geranium seeds should sprout in about a week, but some varieties will take longer than others.
Once the geraniums have sprouted and grown their first set of real leaves, they can be thinned out to one plant per 3 to 4 inches. Thinning out the geraniums allows individual plants to thrive and grow quickly. Care for geranium seedlings indoors until any danger of frost has passed for the zone they will be planted in.
Geraniums can be planted in pots, in the garden, or as part of the landscape. Any spot that has good drainage and gets plenty of sunlight is a good place to add geraniums. Since mature plants can grow to be over a foot wide, place small geranium plants at least a foot apart to give them plenty of room to grow. Once planted, geraniums will flower through the spring and summer, and require little care beyond watering and deadheading old blossoms.