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.
There are many species of Crocus, some flowering in spring, some in autumn, but the natural species are only a commercial commodity amongst specialists, botanical gardens, and educational horticultural establishments. Many of them are lovely garden plants worthy of more extended cultivation. In this volume, however, attention need only be paid to what may be called the Garden Crocuses, the corms of which are sold in hundreds of thousands in the autumn, being mostly imported direct from Holland, where they have been cultivated for generations, if not a few centuries.
The garden Spring Crocus (C. vernus) is universally popular. It is grown by the cottager, the owner of the lordly mansion, by public garden authorities, and by market gardeners, so that the bulb merchants do a flourishing trade. The yellow varieties, including the old Dutch Crocus, come from C. aureus; and the lilac, violet, and white forms come from C. vernus, a native of the Alps, Pyrenees, and Carpathian Mountains. The cost varies from 15s. to 25s. per 1000, according to size, variety, etc, while "mixtures" may be had at cheaper rates.
For outdoor gardening in private gardens and public parks, etc, Crocuses are used in many ways for decoration, either in the grass, beneath flowering trees or shrubs, or as edgings to borders, etc. The market grower, however, is more prosaic, and places the corms in pots, pans, or shallow boxes with the object of selling the plants in various stages of growth. Small shallow boxes about 1 ft. long, 4 in. wide, and 2 to 3 in. deep are popular. The corms are placed side by side, covered with mould up to top of the boxes. These are then covered over with about 6 in. of soil, and are packed away side by side until forcing-time arrives. Some years ago Crocuses were planted in raised beds of good rich soil, and as they were coming into bloom the plants were lifted in little clumps and tied in bundles in moss, and then placed in boxes for market. The modern method is therefore cleaner, easier, less expensive, and the small boxes holding from two to four dozen plants sell well in all stages of growth - either just starting or actually in bloom. Any finely sifted old garden soil does for this purpose, and if early blossom is required the plants may be transferred to a warm greenhouse after root action is well started. It is thus possible to have Crocuses in bloom from Christmas onwards until the first of the outdoor crops begin to bloom.
Amongst the deep-blue, porcelain, and purple Crocuses the following varieties may be recommended: Albion and King of the Blues, deep blue; Baron von Brunow, Dandy, Prince Albert, Sir John Franklin, David Rizzio, John Bright, and purpurea grandiflora, deep purple; Lord Pal-merston, purple; L'Unique, reddish violet: Margot, porcelain blue; Motley, purple; Othello, blackish purple; President Grant, lilac; President Lincoln, purple violet; Von Moltke, dark violet, striped.
Amongst the white spring Crocuses are these: Caroline CJdsholm, Grandeur Triomphante, King of the Whites, Lady Stanhope, Mont Blanc, Queen Victoria, White Queen (Reine Blanche), La Majestueuse, Albion, Madonna Mina, Sir Walter Scott, and Alfred Tennyson - the last five having violet stripes.
Among the yellow Crocuses the dwarf Cloth of Gold (C. Susianus) and the Large Yellow or Mammoth are the best.
Amongst natural species worth growing in large quantities are sativus, the Saffron Crocus, purple lilac with violet veins; speciosus, bright blue autumn; zonatus, autumn, rose lilac with an orange throat; C Imperati lilac purple, veined outside; C. bijiorus, known as the "Scotch" or "Cloth of Silver" Crocus, with many varieties with colours from snowy white to rosy lilac, pale purple, mauve, etc. C pulchellus is a lovely autumn-flowering Crocus with bright-lilac flowers having a yellow eye slightly striped.