This is one of the more traditional perennials for old fashioned window boxes, not only because it cascades downward to avoid obstructing associated windows, but also because, back before window screens were commonly available, the aromatic foliage was purported to repel mosquitoes. Ivy geranium, Pelargonium peltatum, is splendid for hanging pots and retaining walls as well.
The best bloom is usually later in summer or in early autumn, but sporadic bloom can continue almost throughout the year. The flowers are very similar to those of more common zonal geranium, but perhaps more abundant. The slightly more extensive color range goes beyond hues of white, pink, red and peach, to include rich burgundy, pinkish lavender and candy striped red with white.
The rounded and lobed light green leaves are rather succulent, so are easily damaged. Some cultivars have slight foliar halos (semicircular zones of darker color around the centers of the leaves) almost like those of zonal geraniums, but not quite as prominent. The thin and nearly succulent stems are easy to root as cuttings. Although fragile, they can sprawl or cascade as much as six feet.