MULCHING is a process about which much has been said and written, but of which, it is to be feared, very little is known and understood. The very objects of mulching do not appear to be properly appreciated by many persons. Its uses are two-fold: primarily, to keep the surface of the earth moist by preventing evaporation, and to maintain that open, friable condition we always find in the forest, under the natural mulching of the leaves. Mulching keeps the earth cooler in summer and warmer in winter; the first, by shading from the burning rays of the sun, the second, by protecting from frost; the material itself, and the confined air among it, being bad conductors of heat. Now, what material shall we use for producing these results? Almost anything that will fulfill these indications will answer--either stones, chips, boards, twigs, saw-dust, tan-bark, weeds, straw, either long or cut, coarse manure, hay, freshly-cut grass, or, perhaps the very best for all the purposes of mulching, leaves themselves, except that they are difficult to retain in their place. A combination of leaves and twigs, small branches or weeds, may be made to answer a very good purpose, for winter mulching especially. For summer mulching there is another material which has been found to answer an admirable purpose, though not mentioned in the above list; it is mellow earth--yes, mellow earth admirably fulfills most of the conditions of a good mulching material, but it must be kept mellow by constant stirring. The air is thus admitted, and deposits its moisture whenever the earth is cooler than the atmosphere; the presence of the air among the particles of the soil makes it a worse conductor of heat than when it is compacted together. Mulching the newly-planted trees is a very valuable application, whether in summer or winter, and should be practiced wherever it is possible, always remembering that we can not well combine with it culture, which, for the summer treatment, is most essential to the successful growth of trees, and in winter we shall present a harbor to the mice if the mulch be placed too near the tree. He who may have been induced, by the recommendations of high authority, to plant an orchard in a stiff blue-grass sod, or who may allow such sod to surround his trees, in the belief that this constitutes a good mulch, will be sadly disappointed; for, though the surface is shaded, the grass will absorb the moisture from the soil at the expense of the young trees. Clover, on the contrary, makes a denser shade, and seeking its supplies more deeply, is less injurious, while its abundant broad foliage attracts ample supplies of dew to irrigate the soil. In this respect it resembles the Indian corn, which is considered the best crop to put among young trees, as it produces shade, attracts the dew, and, more than all, it demands and receives the thorough culture which the trees also require. CHAPTER VIII. SELECTION AND PLANTING.