AT the close of an article on "Transplanting," in our March number, we promised A sorne hints on after culture, which we now proceed to give as far as relates to the cultivation of the soil.

John J. Thomas, who is a close and accurate observer, and by no means prone to make exaggerated statements, says in his treatise, The American Fruit Culturist, that more trees are lost from negligent and improper treatment after planting, than from all other causes combined. The conductor of one of the most extensive nurseries in this country - a man of great experience and very extensive observation - said to us, a short time ago, "I know of no way in which you can do horticulture a greater service, than to urge upon people who plant trees, the importance - nay, the downright necessity - of better cultivation than that which prevails at the present time." "Every day," said he, "they come here and make long and bitter complaints that their trees have died, or have made no growth; and wherever I go, I see trees in orchards, gardens, lawns, and pleasure-grounds, in a stunted, sickly, and dying condition, mainly in consequence of careless and unskillful culture of the ground. If the evil can not be completely reached through the press, the friends of arboriculture should raise a fund, and employ a competent person to go out as a missionary among planters, and preach on this text, 'Good Cultivation.' If it were possible to compute the loss which this country sustains annually in the mismanagement of trees, the result would be astounding".

We are well persuaded, from our knowledge of the manner in which trees are managed, that there is great room for improvement; and not merely among the agricultural classes, whose attention is chiefly absorbed in their farm crops and stock, and who consider trees as of comparatively little importance, but among those who give a large share of attention to horticulture, and have learned to appreciate both its pleasures and profits. Some are careless: they get their trees planted, and no doubt intend to give them all necessary attention, but unfortunately they forget; other matters more pressing, and for the time apparently more important, present themselves, and the poor trees are left to fight their own battles as best they can. Others are careful and attentive to their trees, but do not really understand what good cultivation is; while they flatter themselves they have done everything for them that could be done, they have scarcely done anything useful or effective. The misfortune is, a very large portion of those who plant are not half in earnest; they go about it without the slightest experience; and instead of making a deep and thorough search for information in books, and in the example set by experienced and successful cultivators, they are satisfied with the merest inkling of information - a simple say-so of a neighbor, which is as likely to be a false guide as a true one, This will never do - there is no excuse for ignorance now in this country; books and periodicals are numerous and cheap, and examples of.

We have observed that within the past year or two, new zeal has been awakened among the better class of cultivators, on the subject of high culture. Instead of devoting their time and attention to the collection of new, rare, and wonderful things, they are endeavoring to bring old, well-known, and well-tried objects, to a higher and more perfect standard of perfection. And this is a hopeful sign. We have no admiration to bestow on a collection of ill-grown, half-starved trees and plants, however rare and varied it may be. It affords us no pleasure, nor can we see how it affords any one pleasure, to see trees and plants pining under neglect and bad treatment. As well might we take pleasure in gazing at an unfortunate prisoner through the iron grating of his dismal cell. Give us half a dozen trees well cultivated, with health,, vigor, luxuriant beauty, and productiveness, expressed in every leaf and limb, rather than an hundred lean and hungry. Give us one dish of well-grown, beautiful fruits, rather than bushels of "windfalls;" or one pot-plant showing in its well-proportioned form and luxuriant growth skillful and careful training, rather than a houseful of lanky specimens that speak to us only of pot-bound roots, bad soil, careless watering, and bad ventilation. "Whatever you do, do it well," should be the motto of every cultivator.

It is unnecessary to say that the health and vigor of trees depend almost entirely upon the condition in which the roots are placed, because the roots perform the important office of feeders. The spongy points, or extremities of the roots, are like so many mouths, through which the supply of food must pass; and if these are bound up in a compact mass of earth, impenetrable in a great degree to air and moisture, it is impossible for them to find the necessary supply of food. No matter how rich the soil may be, if not in the proper mechanical condition, its fertility will be of no avail; because the chemical combinations which prepare the food of trees and plants can not go on in the absence of air and moisture. Here lies the prime defect of cultivation generally; it is not deep and thorough enough to reach the roots. We see people who call themselves very careful cultivators scratching the surface of a narrow circle around their trees with a common hand-hoe, and flatter themselves this is good culture; but if they reflect a moment, they will see their error. What they have done is a mere mockery - no better than the scratching of a sprightly bantam.

The points of the roots extend further from the tree than most people suppose; and the earth should be kept completely pulverized all around them, and beyond them some distance. Anything short of this is labor lost.

Nurserymen have good opportunity of ascertaining the influence of deep and frequent loosening of the soil. The usual practice in this country is to plow between the rows of trees, as deeply as a one-horse plow can go with safety to the roots, and then to follow with a cultivator or horse-hoe. The plow is used two, three, or four times a year, according to the stiffness or looseness of the soil, and the cultivator as often as once a fortnight say from May to October. This is not only an economical mode 0r culture, but, in this country, the very best that could be followed. It protects the trees against the effects of our long and severe drouths. It is very common to see nursery trees, thus treated, in a fine growing condition; while others, that have been merely surface-dressed with a hand-hoe. are completely at a stand still. If we turn over ground that has been kept finely and deeply pulverized by frequent stirring, we find moisture even in the dryest times; while ground that has been left unstirred until it has become hard on the surface, will turn up as dry and as warm as though it had been baked in an oven.