Draining
Efficient Drainage is one of the most important points in connection with the cultivation of garden crops. No plant will succeed in an undrained soil, which soon becomes sour and water-logged, either in a pot or elsewhere. Placing crocks or other porous material in pots, in such a manner as to allow of the free passage of superfluous water from the plants, for a considerable time, if necessary, cannot be too carefully practised. In Draining the whole or any part of a garden, a few important conditions will have to be considered. First, it should be known whether there is an accumulation of land water near enough the surface to cause injury, or if it is the surface water only that will need to be conducted away. This will depend a great deal on the tenacity of the soil. Land, somewhat light on the surface, with a gravelly sub-soil, will generally be sufficiently porous underneath to allow all such water to pass away naturally without Drains, excepting those required for the walks. Heavy soils, with a sub-soil of clay, require an efficient system of Drainage to render them fit for the cultivation of fruit-trees or any garden crops. Water collecting underneath the surface is the greatest evil. If this be removed, the surface water will naturally follow, and must, of necessity, be succeeded each time by fresh air. A main Drain, large enough to receive and conduct the water from all the branches along its course, should be first inserted. A means of outlet lower than any part of the land to be Drained, is necessary, and the main should proceed in a tolerably straight line from the highest point to this, with an equal gradient throughout. The branches may be arranged at right angles, at distances of 15ft. to 20ft. apart, according to the quantity of water that accumulates, or the nature of the soil. Pipes 3in., or even 2in., in diameter, will generally be large enough; their position should be fixed beforehand, and sockets inserted in the main for their reception. Tools specially employed for Draining are the best, being made long and narrow, to admit of digging trenches deep without being wide. A main Drain-pipe, 6in. in diameter, will conduct away a large quantity of water, and this, with its outlet, should be sufficiently deep to allow a fall for all the branches connected. The requisite depth for Drains varies with different soils, 3ft. to 4ft. from the surface being that generally adopted. Glazed and common pipes are both largely used. The former are the most expensive, but are very strong, and best suited for mains. These should be fitted together closely, and, if laid near trees, the joints cemented, to prevent roots from entering and eventually choking them. Draining, to be effective in its results, must be systematically carried out, and each pipe inserted firmly in its proper position. A covering of stones, broken bricks, or similar material, placed over them before filling in the soil, will greatly assist the percolation of water. Some persons prefer laying the main and branches at the same time, thus finishing all as they proceed. This is immaterial, if all the levels have been previously properly obtained. It is, however, safest to insert the main Drain first, as a failure in its action will cause the whole to be useless. In either case, the work should be commenced at the highest point from the outlet, afterwards proceeding with a regular fall towards it. An ordinary spirit level, fixed in a long straight-edge, will indicate at once the fall in that distance, supposing the Drain is not too deep to admit of the bubble being seen. Where the ground is nearly flat, the spirit level is frequently used on each pipe; and, on the other hand, where the incline is certain, the fall may be easily seen by the eye.