There are at least 250 species of geranium. The annual type is familiar from planter boxes and borders, usually a cheery red with upright scalloped foliage. Hardy geraniums are also known as cranesbill geraniums and are vibrant spreading plants with a vigorous growth habit. The flowers of the cranesbill are small, with five petals, and vary in color from white and pink and to purple. The flower develops a long, narrow seed pod — hence the name "cranesbill," as it resemble a bird’s beak.
Hardy geraniums are true geraniums and are hardy in Zone 4 to Zone 9. Blooming usually begins in May and continues until midfall. The beak-like seed pod is formed shortly after the petals open on the flower and grows as the flower declines. The seed pod is the fruit of the plant. It develops a papery exterior as the seeds within mature. The seed pods crack open quickly lengthwise to release and scatter the seed. The action is sudden and violent and can propel seeds up to 35 feet away from the plant.
Hardy geranium seeds are thrown away from the plant with great force and are finely reticulated and small. The seeds are often eaten by mourning doves, white-tailed deer and bobwhite quail. Hardy geraniums can self-propagate when the seed lands in a hospitable location. Plants that start in this way may not be true, however. If there are other species of geranium nearby, the pollens can cross and create new mutations and characteristics.
Growing hardy geraniums is not difficult. Seed can be sown indoors eight to 10 weeks before the last frost or outdoors after the last frost. Germination time can vary hugely, depending upon variety. Most germinate in 30 to 90 days. Once germination is achieved, the plants grow very quickly. Hardy geraniums prefer a site with part sun/part shade, well-drained soil and good organic matter.