The increase in the taste for winter-flowering plants, within the past five years, has been even more positive than that for the cultivation of plants out of doors, formerly it was rare for florists to fill an order in the fall, but now, during the months of October, November, and December, they make shipments daily in large quantities to every section of the country; and these nearly equaling in number those of plants for the open ground in May and June. The plants best suited for flowering in winter may be divided into two classes. First, those requiring a moderate temperature at night, say an average of 50 degrees. Whether the plants are grown in the parlor or sitting-room of a private dwelling, or in a greenhouse especially constructed for their culture, the conditions should be as nearly as possible the same; that is, uniformity of temperature ranging from 45° to 55°, and an avoidance of a dry atmosphere; it is easy enough in the greenhouse to get a properly humid atmosphere by sprinkling the paths with water; but in a room in the dwelling house, the only thing that can be done is to place pans of water on the stove, furnace, or whatever may be the source of heat. If plants are kept in a sitting-room or parlor, an east, south-east, or south aspect should be chosen. Plants of the class that may be grown at an average temperature of 50 degrees, are Azaleas, Abutilons, Ageratums, Carnations, Cinerarias, Catalonian Jessamines, Cape Jessamines, Camellias, Callas, Chorizemas, Geraniums of all kinds, Hibiscus, Hyacinths, Myrsiphyllum, (Smilax), Maher-nias, Primulas, Stevias, Roses, Violets, and the various kinds known as greenhouse plants, which, together with those above named, can be found fully described in the florists' catalogues.
The second class, or hot-house plants, require an average temperature of 60 degrees at night, the range of which, however, may occasionally run from 55° to 65° without injury. Of these we name the following: Begonias, Bouvardias, Clerodendrons, Euphorbias, Epiphyl-lums, Fuchsias, Heliotropes, Poinsettia, Roses, (these will do in either temperature), Tuberoses, etc. For descriptions of varieties, reference may be made to the catalogues. The necessity for this difference in temperature is not absolute, as many plants will do partially well in either; but we make this distinction as a guide to those having a choice of temperatures, in order that they may select the plants that are best adapted to the one at command. In a greenhouse, particularly if heated by a flue, there is often a difference of five or ten degrees between one end and the other; in such a case the plants named in the first class must be placed at the cool end, and those of the second class at the other.
One of the most troublesome pests of plants grown in the greenhouse, or sitting-room, in winter, is the aphis, or "green fly," as it is termed; we have no difficulty in getting rid of it in the greenhouse, when it is separate from the house; all that is necessary is to get some tobacco stems (such as are thrown out as refuse by cigar makers), and soak them in water for a minute or two; about half a pound or so for a greenhouse 25 x 20 feet is placed over a small handful of shavings, only enough to light the dampened tobacco, as too many might injure the plants by smoke; the burned tobacco stems give out a smoke that is quickly fatal to the "green fly." To thoroughly prevent the least appearance of this insect, the greenhouse must be fumigated every four or five days. We fumigate all our greenhouses twice each week during the entire year; our rule being that an aphis must never be seen upon any plant in the houses. If the greenhouse is attached to the dwelling, so that the tobacco smoke would find its way into the rooms, recourse may be had to another remedy; take these same waste tobacco stems and steep them in water until the liquid is of the color of strong tea, with this water syringe the plants freely twice a week, this will not only effectually destroy the green fly, but will keep in check most other insects that infest plants. Where only a few plants are kept in rooms, the easiest way is to dip the plants entirely in the tobacco water, moving them up and down in the liquid, to wash the insects off if they have a firm hold. The "red spider" is another pest to winter blooming plants, and wherever it is seen you may be certain that the atmosphere has been too dry, and very likely the temperature too hot, as it is rarely found in a cool, damp atmosphere. The treatment for this insect in the greenhouse is copious syringings with water, but where but a few plants are grown in the house, it is best to go over the leaves, especially on the under side, with a wet sponge. The red spider is so minute that it is hardly distinguishable by the naked eye, but its destructive effects are quickly perceivable, as the leaves upon which it works soon become brown, and if the leaves are closely examined, particularly the underside, the minute insect will be seen in great numbers.
Another troublesome insect among plants that are grown in a high temperature is the "mealy bug." The insect is flat, of whitish brown, usually nestling at the axils of the leaves, where it is covered with a white powder, making it easily distinguishable; this is one of the most annoying of all insects that attack plants, as nothing seems to kill it, unless the remedy is strong enough to injure the plants; so that rubbing it off with a small brush is the only safe remedy that we would care to recommend to amateurs. We find alcohol thrown on by what is called an "atomizer," sold by druggists for bedewing with perfumes, to be very effective in destroying the "mealy bug," as the alcohol reaches to every part of the plant, but we also find that some plants when in very soft growth are injured by even this light application of alcohol. Another pest, not an insect, but a vegetable parasitic growth known as mildew, affects but few plants in-doors except the rose, still as it is most injurious to those, we give the most effectual remedy for destroying mildew on roses either outside or under cover. Boil one lb. of lime and one lb. of sulphur in two gallons of water, until it is reduced to one gallon; allow the liquid to settle until clear, and bottle it for use; one gill only, no more, of this liquid, is mixed in five gallons of water, and this syringed thoroughly oyer the rose plants in the evening. If in the house, so that syringing cannot be done, dip the plants in it as recommended for the tobacco water. As with most other remedies, we prefer to use this lime and sulphur mixture as a preventive rather than as a cure, and we apply it to our roses at least once a week, even though there is no appearance of mildew. In proportion as plants are kept free from insects and mildew, so will be their vigor and their thrifti-ness. For more complete information see special chapter on insects and mildew.
I may here warn the amateur against the too common practice of placing plants in too large pots. As a general thing, when plants are received from the florists, they are sent without pots, and are usually in a condition requiring them to be shifted into a pot larger than they had been growing in; for example, if they have been grown in a pot of 3 inches diameter, place them in one a size larger, or 4 inches in diameter; if they were in 4-inch pots give them one 5 or 6 inches across, and so on. Though we entirely ignore the use of crocks, or drainage in pots in our own practice, where we have always the proper sizes to use in potting, yet in cases where a suitable sized pot is not on hand into which to shift, (for example, if a plant that has been grown in a pot of 3 inches diameter, must be put in one of 6 inches), then by all means fill up one-third of this too large pot with broken pots, charcoal, or some such material to drain off the surplus moisture that would otherwise be injurious, in consequence of the pot being too large for the plant; but if the pot into which it is shifted is properly adjusted to the wants of the plant, the putting in of crocks for drainage is worse than useless, I care not what the plant may be. Our greenhouse establishment now covers nearly two acres, yet not a pot is so "drained." The need of a larger pot is shown by the earth becoming so filled with roots that they well coyer the outside of the ball, but shifting into a larger pot should be done while the roots are yet white; if left until the roots get thoroughly matted, brown, and hard, it is too late, and the future growth will be seriously retarded. If the plant has been allowed to reach this condition, which we call "pot bound," it is best to lay the ball of roots on one hand and slap it smartly so as to loosen it; by this treatment the new fibres strike out more readily from the hard roots than if left with the ball still compact. After shifting a plant, give it one good watering, so that the soil will be thoroughly soaked to the bottom of the pot; but after that, keep rather dry until there are indications of new growth. For manner of potting, see chapter on "The Potting of Plants." We are often asked as to the use of guano and other fertilizers on in-door plants. As a general thing we use none in our own practice, preferring to shift the plants into fresh soil at the proper time, rather than to do so, and we would advise the same to our friends of less experience, for the use of all such stimulants is, under certain condition of the plants, dangerous in unpracticed hands.