This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
A fine strong-growing European perennial, 3-5 ft., with graceful pinnate leaves, and spikes of pale-blue Pea-like blossoms borne in great profusion in summer. The white variety alba is even more charming, and sells better. There is also an attractive blue-and-white variety called bicolor. There is another kind, orientalis, from the Caucasus, with bluish-purple flowers. The plants grow in any garden soil, and are useful for cutting. They are readily increased by division or from seeds, each established plant requiring about 1 sq. yd.