Simple tips to help grow geraniums
Geraniums of the genus Pelargonium generally do best in sunny locations, but some of the large flowered varieties grow and flower best if they receive light shade in the afternoon.
Select a fertile well drained soil. Work in a complete fertilizer, such as 10-10-10, before planting, especially if the soil is low in fertility. You can also improve the soil structure by working in a two-inch layer of peat moss before you plant. This is very important if the soil is mostly sand or clay.
Once established in the garden, geraniums require little care. To encourage flower production, remove spent blooms regularly. Also, remove yellowed leaves and pinch or trim back stems to encourage branching.
Geraniums will do quite well during dry periods. However, they will flower better if they receive regular watering. Water in the morning, because evening watering might promote diseases.
http://www.stltoday.com/suburban-journals/metro/life/simple-tips-to-help-grow-geraniums/article_8033fa65-8379-567f-a99b-7b84f1ac9894.html