This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
Mr. Beaton describes his method of treating these favorites, thus:
We have them in bloom in the conservatory from the end of June to the latter part of September; but they would do in the smallest greenhouse just as well, and also in living-rooms, where Geraniums are flowered. When the bloom is nearly over, we keep the pots rather dry; and as the flowers and foliage begin to look seedy, we move them out of sight to the top shelf along the back wall, close up to the light, and under the constant draught of air, in and out, night and day, till after the middle of November; by that time the soil is as dry as Scotch snuff, and the "roots'1 are as thoroughly ripe as if the pots were in an Orchid house.
After the roots, or tubers, are thus ripened, we have proved most conclusively that they will keep all through the winter as safely and as long as late Potatoes, if they are kept quite dry, and free from frost, and from the influence of the air. The whole secret for resting Gloxinias and Achimenes for a very long period, or from the fogs of November to the April showers, is to keep them carefully excluded from the air. The simplest way to do that is to shake all the soil from them, and to put each kind into a separate bag of coarse paper, with its name, or tally, or number stick, along with it; the name might also be written on the outside of each bag. The mouth of each bag is tied as close as a bladder, and all the bags are put loosely into a basket, and the basket is put by in a warm closet in-doors. I have grown thousands of seedling Gloxinias before there was a hybrid in the family, and had my share of them ever since; but I confidently assert, that I never had a finer or more plump looking set of bulbs than I saw last week, when one set of the Gloxinias were unbagged.