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.
"Not long since I was at a friend's, and, N on going through her conservatory, was much struck with the luxuriant growth of a Calla. The leaves were home on stems three feet or more in length, and such leaves! I never dreamed that Calla leaves could grow so large before. They were of the richest green, too; and everything about the plant indicated that it was in the most perfect health. It had one bud, on a stalk three feet long, which was as large as my Calla buds had ever been when they had attained full growth, and were ready to unfold; and this bud was hardly half matured, thus giving promise of becoming an immense flower if nothing happened to prevent its developing.
I asked the secret of such magnificent success in Calla growing, and my friend told me in what it consisted. In June she takes her callas out of doors, and turns the pots containing them over on their sides under a tree, or in some shady place, and there she leaves them through the hot summer months, giving them no attention whatever. Of course the old leaves die and fall off, and the earth in the pots bakes into the consistency of brick; one would think such harsh treatment would be the death of a flower, but, on the contrary, the Calla likes it. In September she brings the pots in, and begins to give the plants water. A very short time suffices to start them into growth. As soon as* the leaves appear, she makes the water quite warm. The result is, that her Callas are superior to any I ever saw before. She boasts on having larger flowers than any one else, and, judging from the size of the half matured bud I saw, she has foundation for saying so. She tells me that her Callas are never without flowers through the winter, often as many as four or five open at once.
She never removes the new ones which form about the old plant, but, as they grow, shifts the plants into large pots.
I have seen so many sickly, spindling Callas that I want to have my friends try this method; I am trying it; I put mine out of doors last summer, and brought it in two months ago, and it is flourishing finely. It is an easy plan to try, and I am sure it is a successful one. I ought to have said before that my friend's conservatory is heated from a stove in the sitting-room, therefore this treatment will apply where only a few house plants are kept, and steam-heating is not used.