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 Sweet William is one of the best known and most admired of hardy garden flowers, having been grown for centuries in English gardens. The present fine race has been evolved from Dianthus barbatus, which, in the wild state, is native of Europe and of comparative insignificance to-day. Perennial by nature and distinctly so, the improved races we have now in mind, and for commercial gardening more particularly, are best regarded as of biennial duration only. Hence the periodical raising of the plants from seeds becomes virtually a necessity.
The seeds should be sown early in April in a well-prepared bed of soil in the open, or in pans or boxes in frames, or in the cool greenhouse in the case of a particularly good strain. Indeed there is much to be said in favour of the latter method generally, such as quicker and more certain vegetation of the seeds, and freedom from the attacks of slugs and other pests.
Like other members of the Carnation family the seeds of the Sweet William vegetate promptly, and in cool greenhouse or frame, sown at the time named, they will be above ground in from fourteen to twenty-one days. Thin sowing and early transplanting are essential, and upon a full appreciation of these a full measure of success depends. The Sweet William is so perfectly hardy that no coddling of any kind under glass should be permitted. Plant out in August or September in open quarters, or earlier if a good watering can be given. Grown for the sale of their roots alone, 8 in. apart will be a sufficient distance. If grown for seed-saving purposes - and the best strains are highly desirable from this point of view - not less than 18 in. from plant to plant should be given. The Sweet William may also be raised from cuttings inserted in a cold frame in August or thereabouts. Indeed novelties of merit, until the seed strain is fixed, must be so treated, and so, too, the double-flowered varieties, of which D. b. mag-nificus is the most desirable. (For other kinds of Dianthus see p. 35).
Of varieties, Pink Beauty and the Auricula-eyed are among the more distinct. There are others, too, in scarlet, white, and crimson. [e. h. J].