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.
Popular stove or greenhouse tuberous plants with hairy fleshy leaves, large tubular flowers with exquisite shades of colour and variously blotched and speckled. They are easily raised from seeds sown on nicely prepared gritty soil between January and March, and again in June and July, in a temperature of 70° to 75° F., and plants may be had in flower in six months' time. Old stock plants may have the tubers divided, or new plants may be raised from incisions made across the midrib and main veins of leaves pegged down on gritty soil or leaf mould. Once established, Gloxinias will grow in a cooler atmosphere and will last longer in blossom. For wreaths, crosses, bouquets, etc, it is astonishing how long the flowers of cool-grown Gloxinias will last, but they are very rarely used in this way by florists.