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.
The plant known as "Sweet Scabious" or "Mournful Widow' is often grown for cut flowers in quantity. It is raised from seeds every year, being an annual, and in July and August produces its flower heads of crimson, white, purple, yellow, lilac, and intermediate shades, according to variety, in great profusion on stems 2-3 ft. high. There are many varieties, all worth growing for their beauty. The seeds may be sown in shallow drills, about 12-18 in. apart, in March, April, and May to keep up a succession, or in September to secure an early supply of bloom the following year.
S. caucasica is a handsome Caucasian plant, 1-3 ft. high, really a perennial, but often grown as a biennial. The soft lilac-blue flower heads, 3 in. or more across, borne on stems 2-3 ft. high, are much appreciated. There are several varieties, including a white one. The seeds may be sown in gentle heat in February and March to plant out in April; or in May to transplant in September for flowering the following year.