Green-house plants, being now in an absolutely inactive state, require little more water than merely to keep the earth about their roots from becoming perfectly dry, by occasionally applying a very small quantity at the root; and, if done with a watering pot, as described under this head in the Hot-house of this month, very little will be spilt in the house to increase dampness, which, if it does appear, by any of the leaves of the plants becoming musty, they must be instantly picked off; and, if it increases, give a little fire and air. Succulent plants will not need any water during this month, unless omitted in December.
CAMELLIA JAPONICA.
This magnificent and attractive flower, with all its splendid varieties, will, about this time, begin to open its beautiful flowers. But for this admired genus of plants, our Green-houses, at this season, would be void of allurement. It is, in this country, subject to mildew and red spider, and more especially in the city, which appears to be from the nature of the air. The effects of mildew on these plants, if not prevented, would prove fatal; as, from appearance, many have died by it in our city. If it has reached a great extent, the leaves are brownish, having the appearance of being decayed, or scorched with the sun. In taking hold of the leaf, it feels soft, and altogether seems to have lost its nutritive substance; and, when the young foliage expands, it becomes covered with dark brown spots, and finally very much disfigured; and, when in this state, it is attacked by red spider, and, ultimately, death ensues.
If any of the plants are affected as above described, take a sponge, and wash every leaf minutely with soft water, and syringe them with water three or four times a week, which will clean them. All the young foliage will be healthy, and that which has been affected will fall off. However, prevention is better than cure; and if the Camellias are properly syringed every evening during summer, and once or twice a week during winter, they will never be subject to the ravages of mildew or of red spider.
Tie up any of the flowers that are expanded to stakes, in case of accident; and, in syringing, observe not to let any water fall on the flowers, as it causes premature decay, and change of colour.
The mildew first appears like small particles of very fine flour, around the under edge of the leaves, and visible to the naked eye; so that, syringing, sponging, &c. under the leaf is most requisite; but, as the mildew extends, both sides of the leaves are covered with these white particles.
OF ORANGES, LEMONS, &c.
As there will perhaps be more leisure in the Green-house this month than in any other during the winter, it is presumed that there will not be a moment lost. If any of the trees are infested with insects, these, being now in their inactive state, may be more easily destroyed than at any other time. It is the brown scaly insect that generally infests them. For treatment, see Hothouse, January. The plant, or tree, after being washed, before it becomes dry, will require to be syringed with water, otherwise the dust will adhere to the glutinous particles of the soap. Set the plant in an airy situation to dry, in case of damp. There are several others subject to this insect, such as Myrtles, Oleas, Oleanders, &c. which treat in the same manner. Be careful that these trees are not over watered; if the soil is moist, it is sufficient.