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.
Showy hardy annuals 1-2 ft. high, of easy growth in any garden soil, raised from seeds sown under glass in January and February for early blooms, or in the open in March, to flower from June onwards. G. elegans, rich crimson, and C. pulchella, rich purple, are both excellent. They sell in pots or shallow boxes in spring.