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.
Artificial heat will now be required, and as the systems of heating are various, many are doubtful as to the most economical. The old-fashioned hot-air flue and furnace is so seldom mentioned, that it is very generally considered to be superseded by other methods. For small houses, it is, however, the most economical. The cost and expense of fitting up a hot-water apparatus is so great as to deter its introduction into small establishments. It is well known among cultivators, that as good plants and flowers have been, and still are, produced in houses warmed by flues, as in those that are heated after the most approved methods by hot water. Success in plant culture does not depend upon the method of producing artificial heat, although much depends upon its proper application. One of the largest and most unique conservatories in this country, was heated for several seasons by a branch from the furnace used in heating the dwelling to which it was attached, and small structures of this description have frequently no other means of being heated than by simply opening the communicating doors into the parlor.
Thus we see that various simple expedients have been perfectly successful, and although water in pipes is undoubtedly economical on a large scale, or where several contiguous houses are warmed by one furnace; still, for small greenhouses, a flue is generally preferable. Flues should always be constructed with evaporating pans on the covers. These being filled with water when the fire is strong, counteract, to some extent, the aridity which at all times results from artificial heat.
Great care should now be exercised in watering. Plants of a tender nature, and those in a state of rest, should be kept as dry as consistent with health to render them proof against change of temperature.
By day the temperature may average 60° or 65° and at night 40º. Keep your tender plants in the warm end, and water those most that are in flower. Pinch the points of the shoots of plants intended for the flower garden to make them stocky and strengthen their growth. Syringe your camellias freely in fine Weather. Fumigate twice a month to keep down the green fly, and throw a small quantity of sulphur occasionally on the heating apparatus to destroy red spider.
Set a few of the finest caloeolarias aside, to save seed from, and water them occasionally with liquid manure. Geraniums in flower will require more water than at any other time. A slight shading will help to preserve the blooms. Primula seed for early winter flowering plants, should now be sown. Do not take any of the hard-wooded choice plants out of the house until their growth is well advanced. Heaths, epacris, lesohenaul-tias, pimeleas, etc, do as well in the house until August. Put in cuttings of chrysanthemums; those that are potted should be well pinched down for the next six weeks, in order to have bushy, well-flowered plants in the fall. Put them in 8-inch pots, to flower; stand them out in the sun, and keep them regularly supplied with water. The small flowered kind are beautiful pot plants. Put in a few heliotrope cuttings for flowering early in winter. Aehemenes, gloxinias, gesneras, etc., will now require attention in potting and tying out; for such as Aehemenes coccinea, A. longiflora, and A. rosea, a few twigs of any kind form the best means of support. A moist atmosphere is indispensable for the perfect growth of these plants. The dwarfest kinds do well in hanging baskets.
Admit air chiefly by the top ventilators; when both top and bottom ventilators are open, it is scarcely possible to keep a sufficient degree of moisture in the air. Let the ventilators remain open all night, unless the thermometer ranges below 450.
There is much interest attached to the raising of seedling plants; even when the seeds are saved at random, there is always a chance of producing something superior, but under careful hybridization, it is almost a certainty. Seeds of calceolarias, pansies, pelargoniums, and cinnerarias, should be sown this month, so that the plants may be strong before winter. Small seeds, such as the first mentioned, require to be very slightly covered with soil; and, in order to obviate frequent waterings, which is likely to disturb them, cover the pot with a square of glass, and sprinkle a little sand over it, taking care to remove it before the young plants become etiolated. Roses for winter flowering should be lifted from the flower borders and potted; prune the branches, and place them where they will be shaded for a few weeks, until fresh roots are formed; then they may be fully exposed to sun. Fine flowering plants are procured in this way. Cuttings of roses, pelargoniums, verbenas, &o., will root freely at this season, out of doors, if sheltered somewhat from the sun.
Success will be more certain, if planted in a frame having a northern exposure, where they can be protected by a sash, if found necessary, during heavy rains, etc.