This section is from the book "The Gardener's Monthly And Horticulturist V26", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
"J. D.," New York, writes: "I am about to attempt raising violets on a large scale, and I hardly know what way to raise them. Some tell me to use nothing but cold frames, as there is little expense with them. Others say build houses and heat them with hot water. I would like a word or two from some of the readers of the Gardeners' Monthly. I take the magazine and see that you, yourself, answer queries like this sometimes, and if you think this worth such answer I will be very much obliged. Could you give me an idea what it costs a running foot to build a greenhouse 20 feet wide? "
[The very best instructions we can write will not obviate the necessity of some practical experience. But in a general way we may say that violets may be grown either in cold frames or in houses heated with hot water. The latter is preferable and will yield the grower a larger percentage of profit. The cold frames are of course much cheaper and more easily constructed. To prepare a frame it is best to dig a shallow pit, and fill with good top soil, about which build the frame and bank up earth on the outside to the top of the boards. In the winter cover the sash with boards or mats for protection against severe cold. Every sunshiny day remove these covers to give light to the plants, replacing them before the sun goes down. It will probably not be necessary to water the plants during the winter. As soon as the weather will permit give air daily. Cold frame grown violets will yield a good quantity of bloom. One disadvantage in frame grown violets is the difficulty in getting at and picking them during extreme cold weather.
Indoor grown violets should have a house built especially for them, and should be about ten feet wide; the sides being low, say a foot above the ground. Dig a narrow walk down the center, leaving solid beds on each side, which should be as near the glass as possible. The temperature of the house should be kept at about 45-. Give air every fine day during the winter.
Violets do not like bottom heat at all, and very little top heat, therefore the hot water pipes should be placed on the edge of the beds, and only a sufficient amount of feet to heat the house properly.
To grow violets for forcing, as soon as the frost is entirely out of the ground and the soil is dry enough to work, take old clumps of plants, and divide into small crowns and plant out about eight inches apart, in rows sufficiently far apart to allow easy and frequent cultivation.
If double violets be the variety grown, care must be taken during the summer to cut off all the runners, as they prevent good and abundant bloom. If single kinds, this is not necessary, nor do they make many runners.
As the red spider has a partiality for violets, it would be well to plant them in a situation where they may be frequently syringed with the hose during the summer. In the fall lift the plants and plant them in the frame or house as close together as possible. In a house during the winter an occasional hand syringing with tobacco water will be found beneficial, both as a fertilizer and a preventative to insects.
A good commercial house, twenty feet wide, plainly built, with cheap ventilating apparatus and without boilers and pipes, may be built for about $6 per running foot. - Ed. G. M].