POTTING OF PLANTS. When plants are placed to grow in a small earthen vessel, like a garden pot, their condition is very different from that to which they are naturally exposed. The roots have not liberty to extend themselves as they choose, and they are either obliged to grow back upon themselves or round the vessel in which they are confined; they are likewise exposed to great varieties of temperature and depend on an uncertain supply of moisture. It is therefore the object of the careful gardener to obviate as much as possible these evils, and at the same time to secure the advantages derived from the operation itself. These advantages consist mainly in the facility with which it enables the gardener to change the arrangement and position of his plants ; it also, by cramping the roots, diminishes the tendency to form leaves, and increases the disposition to flower. It secures a constant and effective drainage from the roots, and renders it more easy to expose them to a favourable amount of bottom heat, For the raising and nourishment of young seedlings it is also an advantageous process. Exhaustion of the soil is one of the inconveniences which result from this system. In order to remedy it liquid manure should be applied ; or the plants placed in pan feeders, shallow earthen vessels containing manure, to which the roots have access through holes in the bottom of the pot. It is however to shifting mere particularly that recourse should be bad for renovating the soil; and this, if skilfully performed without injuring the plant, is most successful It is not alone for the purpose of improving the soil that shifting is desirable ; the roots if allowed to remain long in a confined space form a hard knotted masa, which is very unfavourable to the retention of moisture and the growth of the plant. All the earth therefore which
clings to the roots should be carefully separated before the plant is placed in the fresh soil. The roots of a plant are always found to be in contact with the sides of the pot, and this being generally composed of a highly absorbent substance, is subject to great variations of temperature. The practice of plunging greenhouse plants into the earth during the summer to obviate this is very undesirable, as when they are again taken up the roots are generally found to have taken advantage of the earth around them and to have fastened themselves in it. The drainage of potted plants is of great importance, and in all eases a quantity of broken pieces of tiles and earthenware should be placed at the bottom of the pots to prevent the stagnation of water about the roots. To be managed perfectly a young plant should be placed in as small a pot as it will grow in, and gradually and successively transferred to large pots as it advances. Dr. Lindley (‘ Theory, of Horticulture ') says, " It is by paying constant attention to the shifting of the growing plant, by the employment of a very rich stimulating soil, and by a thorough knowledge of the kind of atmosphere which suits them best, that have been obtained those magnificent pelar goniums, cockscombs, and balsams, &e., that have so often and so justly excited the admiration of even the most experienced gardeners."