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.
Next to the soil, the water is of the greatest importance to secure a perfect development in the different organs of plants. Wo will as briefly as possible investigate its influence on vegetation. The water is found in the atmosphere as a gas, and in the soil as a fluid, and is in both forms of equal importance to develop plants. We know that no substances can enter through the roots of plants unless in a fluid state; consequently, if water was not present in the soil, the different nutritive substances which it contains could not enter into the composition of plants. This is, however, not the only office which it performs: it also serves to convey the dissolved substances to the different parts of the tree, where new organs are formed. This will con-vince us why some soils, although fertile, but exposed to drought, can not have that favorable influence on vegetation which is effected by a soil of less fertility, but supplied with sufficient moisture. Yet, to have the desired effect upon the plant, and to secure a vigorous growth, the temperature and moisture of the soil must stand in a certain proportion to each other. To make this appear more evident, we will suppose a plant to be placed where there is high temperature, but no water supplied to it.
What will be the consequence? After the leaves, through perspiration, have given off to the atmosphere all the nourishment they could receive through the roots, they will wither and fall off; next, from the insensible perspiration which takes place from the trunk and branches, the sap vessels will dry up; in feet, the plant must die.
If the contrary took place, namely, a cold atmosphere and a superabundance of moisture, the effect would just be of an opposite nature. In the first place, it would cause an excitement in the growth of the tree, which will be very feeble, and therefore not bring forth as many flowers as usual. And should it happen that the roots are surrounded with water, which prevents the access of air to to them, they will be unable to perform their functions, and must rot. The watering of plants, therefore, belongs to one of the most important operations in gardening.
After shifting the Camellias, great precaution must be taken in watering them sparingly until they get settled, when more should be given. Always be sure that the water penetrates the ball of earth; to give them a good supply at once, so that it runs out through the aperture, is better than little and often. The period during which Camellias require plenty of water, is when they commence forming young wood, until the flower buds are perfectly developed; if water is not supplied regularly at this time, many of the flower buds will drop off.
Stringing must also be attended to regularly from the time the Camellias commence their growth. In the winter, watering and syringing should be done early in the morning. Always water before syringing; if this is not done, it is very difficult to judge which pots are dry. It should also be done early in the morning, that the plants may be dry again before the sun gets too strong; often some drops of water will remain upon the leaves, and when the rays of the son fall upon them they act like a burning glass in scorching the leaves. When the flower buds are bursting, syringing overhead should be discontinued; else the tender sepals will be spotted. When moss grows upon the surface of the earth, it is caused from want of drainage. The plant must then be taken out carefully without breaking the ball of earth; after renewing the drainage, replace the plant; now remove about one inch from the surface, and fill it up with suitable compost.
The dropping off of the flower buds may be attributed to different causes; from the plant being kept either too dry or too wet; also to a sudden change in the temperature. If the flower buds are imperfectly developed in the fall, when the plants are brought in the house, the watering must be attended to with a great deal of care.
The cultivation of Camellias in rooms is connected with some difficulty, on account of the dryness of the atmosphere. When kept there, they should be placed apart from the sitting-room, where they are not so much exposed to the clouds of dust which the housemaid raises with the broom, and which finds a landing-place upon the leaves of the poor Camellia, and consequently hinders its healthy development. The red spider is also very willing to make its appearance in a room. Above all, when watering the plants, water them with clear water, and do not force upon them coffee, the dish-water, soap-buds, and other beverages, which place the roots of the poor plant in nothing but a sewer. A good plan is to wash the branches and leaves frequently with a sponge.