The improvements of the last few years in fruit tree culture have been very great, and are very easily extended. From having been pursued in the most careless and slovenly manner possible, it is now perhaps the best understood of any branch of horticulture in America. The importance of deep trenching, mulching, a correct system of pruning, and the proper manures, have come to be pretty generally acknownumber mainly by selections from the numerous good native varieties now springing into existence.

The greatest acquisition to the amateur's fruit garden, within the last few years, has been the cold vinery. - a cheap glass structure by the aid of which, without any fire heat, the finest foreign grapes can be fully ripened, almost to the extreme northern parts of the union. These vineries have astonishingly multiplied within the last four years, so that instead of being confined to the gardens of the very wealthy, they are now to be found in the environs of all our larger towns - and a necessary accompaniment to every considerable country place. As a matter of luxury, in fruit gardening, they perhaps afford more satisfaction and enjoyment than any other single feature whatever, and the annual value of the grapes, even to the market-gardener, is a very satisfactory interest on the outlay made in the necessary building.

Now that the point is well settled that the foreign grapes cannot be successfully grown without the a'd of glass, our most enterprising experimentalists are busy with the production of new hybrid varieties - the product of a cross between the former and our native varieties - which shall give us fine flavor and adaptation to open air culture, and some results lately made public, would lead us to the belief that the desideratum may soon be attained. In the mean time the native grapes, or at least one variety - the Catawba - has taken its rank - no longer disputed - as a fine wine grape - and the hundreds of acres of vineyards which now line the banks of the Ohio, and the rapid sale of their vintages, show conclusively that we can at least make the finest light wines on this side of the Atlantic.

The progress of the art of gardening in this country, considered merely in a useful point of view, is greatly retarded by the want of some school in which native, or at any rate naturalised ability, could be developed. Almost all the practical gardeners in America, are foreigners - generally either Irish, Scotch, or German. They bring with them much experience from the mother country; but much of it is of little value in this climate - partly from its great difference to that of the climate of the north of Europe, and partly because they have only learned the routine of practice, and not the principles of the art. Hence we see every day, gardeners, in this country, where the great want is shade from the burning sun - pruning trees and plants to let the sun in, just as they have been used to do in a moist and foggy climate, where the trouble is to get sun enough to ripen either the wood or fruit. It may be safely said, that half the disappointments in our nicer operations of gardening, arise from this cause. It is, of course, only to be remedied in the main, by the dissemination of sufficient knowledge among the owners of gardens, to enable them to enforce upon the gardener the absolute necessity of remembering that he must change his practice with his country.

If, as we have before suggested, some one of our large Horticultural Societies would establish an experimental garden, where emigrant gardeners could labor for a shows, and anniversary dinners - which have, indeed, become almost fatiguing from their sameness - without the ambition to achieve any larger field of usefulness.

In ornamental gardening, many and beautiful are the changes of the last few years. Cottages and villas begin to embroider the country in all directions, and the neighborhood of our three or four largest cities begins to vie with the environs of any of the old world capitals in their lovely surroundings of beautiful gardens and grounds. The old and formal style of design, common until within a few years, is almost displaced by a more natural and graceful style of curved lines, and graceful plantations. The taste for ornamental planting has extended so largely, that much as the nurseries have increased, they are not able to meet the demand for rare trees and shrubs - especially evergreens - so that hundreds of thousands of fine species are annually imported from abroad. Though by no means so favorable a climate for lawns as that of England, ours is a far better one for deciduous trees, and our park and pleasure ground scenery, (if we except evergreens,) is marked even now by a greater variety of foliage than one easily finds in any other temperate climate.

A peculiar feature of what may be called the scenery of ornamental grounds in this country, at the present moment is, as we have before remarked, to be found in our rural cemeteries. They vary in size from a few, to three or four hundred acres, and in character from pretty shrubberies and pleasure grounds, to wild sylvan groves, or superb parks and pleasure grounds - laid out and kept in the highest style of the art of landscape gardening. There is nothing in any part of the world which equals in all respects, at the present moment, Greenwood Cemetery, near New York - though it has many rivals. We may give some idea of the extent and high, keeping of this lovely resting place of the dead, by saying that about three hundred persons were constantly employed in the care, improvement, and preservation of its grounds, this season. The Cemetery of the Evergreens, also near New-York, Mount Auburn at Boston, Laurel Hill at Philadelphia, and the cemeteries of Cincinnati, Albany,Salem, and several others of the larger towns, are scarcely less interesting in many respects - while all have features of interest and beauty peculiar to themselves.

From cemeteries we naturally rise to public parks and gardens. As yet our countrymen have almost entirely over-looked the sanitary value and importance of these breathing places for large cities, or the powerful part which they may be made to play in refining, elevating, and affording enjoyment to the people at large. A more rapid and easy communication with Europe, is, however, beginning to awaken us to a sense of our vast inferiority in this respect, and the inhabitants of our largest cities arc beginning to take a lively interest in the appropriation of sufficient space - while space may be obtained, for this beautiful and useful purpose. The government has wisely taken the lead in this movement, by undertaking the improvement, (on a comprehensive plan given by us,) of a large piece of public ground - 150 acres or more, lying almost in the heart of Washington. A commencement has been made this season, and we hope the whole may be completed in the course of three or four years. The plan embraces four or five miles of carriage-drive - walks for pedestrians - ponds of water, fountains and statues - picturesque groupings of trees and shrubs, and a complete collection of all the trees that belong to North America. It will, if carried out as it has been undertaken, undoubtedly give a great impetus to the popular taste in landscape-gardening and the culture of ornamental trees; and as the climate of Washington is one peculiarly adapted to this purpose - this national park may be made a sylvan museum such as it would be difficult to equal in beauty and variety in any part of the world.

As a part of the same movement, we must not forget to mention that the city of New York has been empowered by the State legislature to buy 160 acres of land, admirably situated in the upper part of the city, and improve and embellish it for a public park. A similar feeling is on foot in Philadelphia, where the Gratz estate and the Lemon Hill estate are, we understand, likely to be purchased by the city for this purpose. It is easy to see from these signs of the times, that gardening - both as a practical art and an art of taste - is advancing side by side with the steady and rapid growth of the country - and we congratulate our readers that they live in an age and nation where the whole tendency is so healthful and beautiful, and where man's destiny seems to grow brighter and better every day.

Green-House Plants #1

A Lady, (Richmond, Va.) You. will find in Buist's Select Catalogue of " Rare and Popular Green-house and Hot-house Plants," both the list and the information you require. (Address R. Buist, nurseryman, Phila., with 2 postage stamps enclosed.) This catalogue, just published, contains brief descriptions and hints for the cultivation of any genus of plants enumerated.