Plants that are kept in rooms generally are such as require a medium temperature, say 40°. Sitting rooms or parlours, about this season, are, for the most part, heated from 55° to 65°, and very seldom has the air any admittance into these apartments, thus keeping the temperature from 15° to 25° higher than the nature of the plants requires, and excluding that fresh air which is requisite to support a forced vegetative principle. Therefore, as far as practicable, let the plants be kept in a room adjoining to one where there is fire heat, and the intervening door can be opened when desirable. They will admit sometimes of being as low as 33°.
If they be constantly kept where there is fire, let the window be opened some inches; two or three time a day, for a few minutes, thereby making the air of the apartment more congenial, both for animal and vegetable nature.
WATERING, &c.
There are very few plants killed for want of water, during winter. All that is necessary is merely to keep the soil in a moist state, that is, do not let it get so dry that you can divide the particles of earth, nor so wet that they could be beat to clay. The frequency of watering can be best regulated by the person doing it, as it depends entirely upon the size of the pot or jar in proportion to the plant, whether it is too little or too large, and the situation it stands in, whether moist or arid. Never allow any quantity of water to stand in the flats or saucers. This is too frequently practised with plants in general. Such as Cálla Æthiòpica, or African Lily, will do well, as water is its element, (like Sagittària in this country;) and the Hydrángea horténsis, when in a growing state, will do admirably under such treatment. Many plants may do well for some time, but it being so contrary to their nature, causes premature decay; a fœtid stagnation takes place at the root, the foliage becomes yellow, and the plant stunted; and in the winter season, death will ensue.
OF CAMELLIA JAPONICA.
In rooms the buds of Camellias will be well swelled, and on the Double White and Double Variegated sorts, perhaps they will be full blown. While in that state the temperature should not be below 34°; if lower they will not expand so well, and the expanded petals will soon become yellow and decay. If they are where there is fire heat, they must have plenty of air admitted to them every favourable opportunity, or the consequence will be, that all the buds will turn dark brown, and fall off. It is generally the case, in the treatment of these beautiful plants in rooms, that through too much intended care they are entirely destroyed. In the city, they do not agree with confined air, and they cannot get too much of pure air, if they are kept from frost or cutting winds. To sponge frequently will greatly promote the health of the plants, and add to the beauty of their foliage, as it prevents the attacks of mildew. In this season they do not require much water at root, which may be observed in the slight absorption by the soil. See this subject under the head of [Watering].
When the flowers are expanded, and droop, tie them up neatly, so that the flower may be shown to every advantage.
OF INSECTS, &c.
Insects of various kinds will be appearing on your plants. For method of destruction see [Hot-house, January]. It will not be agreeable to fumigate the room or rooms, or even to have the smell of tobacco near the house from this cause.