Garden geraniums (Pelargonium x hortorum) are popular flowering plants for beds, borders, containers, hanging baskets, and window boxes.  Geraniums are easy to grow and provide color in the garden from May to frost.  Flower colors are red, pink, salmon, orange, white, lavender, and bi-colors.  Several fancy-leaf geraniums possess silver, white, gold, red, or purple markings on their leaves.  In past years, most geraniums were grown vegetatively from cuttings.  Today, many plants are grown from seeds. 
 
Geraniums should be planted outdoors when the danger of frost is past.  It's usually safe to plant geraniums in early May in southern Iowa, mid-May in central Iowa, and late May in northern portions of the state. 
 
Geraniums perform best in fertile, well-drained soils in full sun.  Plants will grow in partial shade, but will not bloom well.  For optimum flowering, geraniums should receive at least 6 hours of direct sun each day. 
 
Geraniums respond well to applications of fertilizer.  Prior to planting, apply and incorporate 1 to 2 pounds of an all-purpose garden fertilizer, such as 10-10-10, per 100 square feet of garden area.  Geraniums growing in containers should be fertilized every 2 to 4 weeks with a dilute fertilizer solution. 
 
During dry periods, a deep soaking once a week is sufficient for plants in beds and borders.  Plants in containers require more frequent watering.  Water geraniums in containers when the soil surface becomes dry to the touch.  If possible, avoid overhead watering as wet foliage encourages disease development.  To keep plants blooming continuously throughout the summer, remove spent flowers (deadhead) on a regular basis.  Deadheading prevents seed development and encourages the plants to produce additional blooms.  It also improves plant appearance.