Because the geranium and the pelargonium are so often confused, horticulturists came up with the name "hardy geranium" to distinguish the two. The hardy geranium is a perennial flowering plant, far more hardy than the pelargonium. Growing to a height of 18 to 24 inches, they are used in rock gardens, as bedding plants and also do well in containers. Depending upon where you live, your hardy geranium will bloom in late spring to early fall, in shades of purple, blue, pink and white.
Provide full sun to partial shade, depending upon the variety. There are a few hardy geraniums that need shade, so check the requirements for your particular plant.
Plant your hardy geranium in a soil that is well-drained. This plant is not particular about soil ph or texture. It's always a good idea with most plants, however, to throw 2 or 3 inches of organic compost into the planting mixture.
Water the hardy geranium sparingly, and then allow the soil to dry out. Watering once a week should be sufficient unless the weather is particularly dry or the plant starts to wilt.
Apply an all-purpose fertilizer once, in the spring. A granular 10-10-10 fertilizer, scattered in the garden, will work well.
Prune your hardy geranium in mid-spring by cutting back all dead stems. In late summer, prune the whole plant back to about 6 or 7 inches.