COMMERCIAL GARDENING.

Commercial gardening continues in a flourishing condition. New nurseries spring up in various parts of the country, especially in the west, and most of the older ones go on augmenting their stock, and increasing the extent of their grounds. How far this success can be looked upon as an evidence of the profitableness of the profession of the nurseryman, is a question we shall not undertake to enlarge upon. A country so extensive as ours, and so bare of good fruits, as it is in most instances, must, for a long period, create a good demand for fruit trees; and, from the increasing taste for ornamental planting, a fair demand for trees and shrubs cannot otherwise than be expected.

The introduction of new varieties of fruit, from abroad, and of new seedlings at home, is a subject attracting the attention of zealous nurserymen; at the present time, when so many sorts are annually produced, it is not to be supposed, that all of them will be found to possess great merit; and if, among twenty poor kinds, one of high character is found, it will repay the time, the labor, and the expense, attendant, in adding such to collections. It does not follow, that every amateur should add all the new fruits to his collection that the nurseryman adds to his catalogue. By no means. Yet it would be injudicious, and greatly retard the progress of pomological science, to indiscriminately reject all new fruits, merely because some of them have not come up to the standard of excellence which had preceded their introduction.

In our several volumes, we have annually given some account of the principal nursery establishments in New York, Philadelphia, Baltimore, Washington, and other cities. In our last volume, we have given two articles upon the gardens and gardening of Western New York; these will be concluded in our present volume. We therefore need not recapitulate what we have already stated, in reference to the state of commercial gardening in these places.

In the neighborhood of Boston, there is the usual activity among the trade. The reports of the Massachusetts Horticultural Society will show the great number of fruits which have been exhibited, trees of which will be found for sale in

the principal nurseries. And, while so much care has been devoted to this department, it is gratifying to know, that equal pains have been taken to introduce all the most showy and interesting varieties of hardy trees and shrubs, especially those adapted to the ornamenting of lawns and pleasuregrounds. Of greenhouse, hothouse, and garden plants, a reference to our Floricultural Notices, and to the reports above mentioned, will show how much has been accomplished since our annual summary of 1847.

GARDEN LITERATURE.

Few publications have appeared the last year. The principal have been Gray's Botany of the Northern United States. Tuckerman's Synopsis of Northern Lichens; Transactions of the N. Y. State Agricultural Society, for 1837; Report of the Patent Office for 1847; Rogers's Scientific Agriculture. The two numbers of Colman's European Agriculture, completing the work; and three additional numbers of our Fruits of America, (Nos. 4, 5, and 6;) No. 7 will appear the present month, and be followed in regular order, by the others. A new edition of Allen's Treatise on the Grape, enlarged and revised, has also just appeared, and we shall notice it in our

next.

ART. II. The Blight in Pear Trees. By J. H. JAMES, Esq. Urbana, Ohio.

I OBSERVE, by your notes of a tour to Buffalo, that you have had an opportunity to see the blight in pear trees, as exhibited in the nurseries at Buffalo and at Rochester. You had previously announced your opinion, (Vol. XI. p. 5,) and here again repeat it, "that the blight of the west is not the blight of the New England states," which you call insect blight, and attribute, on the authority of Mr. Lowell and Dr. Harris, to the action of an insect known as the Scolytus pyri. I wish to raise, with you, the inquiry whether you have not too hastily decided that the western blight is different from yours, and

to induce the examination whether the notion of an insect blight rests on any sufficient authority.

Until 1844, I was a firm believer, on the report of others, that the fire blight in pear trees was caused by an insect, and that the spread of its ravages might be checked and prevented by a prompt amputation of the affected limbs, and a consumption of them by fire. In that year, for the first time since I became a grower of trees, I found fire blight in my garden; and, as I had, within a few days previously, heard a paper read by Dr. Mosher before the Cincinnati Horticultural Society, describing minutely the action of these insects, (not the scolytus, however,) and the causes why they had failed to be discovered when sought for, I hastened to apply the knife as he had advised. When I came to amputate the limb, which had caught my eye from a long distance, I was surprised to find that the appearance did not accord with Dr. Mosher's description of the disease, which he represented as "first making its appearance at the extremity of a single branch when in full leaf, and from the young twigs of the present year's growth extending down the limb, to the older wood." In my case, the branch, a strong upright shoot, was six feet long, and about midway of its length for the space of 20 inches, the leaves were of a shining black color, and, during the same extent, the bark was shrivelled, while the extremity of the branch was still green and flourishing.

My examination of the tree did not enable me to discover the presence of any insects, but, assuming that they were certainly there, I cut off the entire limb close by the trunk of the tree, when I found the sap diseased below the bark. According to the books, I expected to find an exhausted state of the sap, not a vitiated redundancy. Two days after, I found the like mark of black leaves on another limb, when I cut into the base of all the limbs, and found the entire top, including the upper part of the trunk, in a diseased state, which I would describe as a putrid fermentation. Between the bark and the alburnum, the sap was profuse, viscid, and discolored, having the smell of a spoiled watermelon. My further observations led me to conclude that this sap dries up after a few days, leaving a brownish color on the surface of the alburnum, followed by a shrivelling of the bark. Mr. Downing

describes this shrivelling as preceding the vitiating of the sap, but I do not so find it. The effect produced is equivalent to that caused by an extensive removal of the bark, and a complete destruction of the tissue surrounding the wood. The circulation of the elaborated sap, in its descent from the leaves, seems to be thus prevented, and, as the branches become exhausted, the blackening of the leaves begins.

During that summer, (12 July,) I addressed a letter to the Cincinnati Horticultural Society, on the subject of blight, which they caused to be published in the Western Farmer and Gardener for August 1844, the essential parts of which were absorbed into Mr. Beecher's Essay of October, 1844, very much in the same way as the theory of that essay is thought to have been transferred into Mr. Downing's book on Fruits which appeared in the ensuing year. From that letter, I make the following extract:

"I am thus minute in giving the appearance of things presented to my view, because, in my searches for descriptions of the disease called fire blight, I find none in the numerous journals I have, and that you may judge whether this be fire blight, as I suppose it is. If this be the disease described by Dr. Mosher, I doubt whether it is caused by the aphis he describes. I find, in my garden, many instances in which the green aphides have destroyed the terminal buds in the young growing shoots, so that the extremities of the shoots wither and die for several inches. The first good bud below, which would otherwise lie dormant, is pushed forward, and becomes the leading shoot. If the brown aphis actually kills the leaf by extracting its juices, would any worse effect ensue than if the leaves were cut off with a knife, which would not kill the limb, unless the succeeding crops of leaves were also removed? I suggest that the disease is, in fact, an infected state of the sap-a fermentation which I cannot think is caused by the brown aphis preying on the petioles of the leaves, and thus preventing a return of the fluids. We are not warranted in supposing that the aphis poisons the sap without some proof; and such a supposition admits that the sap is not all consumed by the insect; nor are we to assume that the sap is consumed by the aphis, for, if we examine sufficiently early, we shall find it abundant and spoiled

smelling as I have described above. It is said in paragraphs which float through the newspapers, that the scolytus pyri works under the bark, and girdles the limb, and kills it. If the ringing thus made by the scolytus should be much more than an inch in width, the limb would probably die, and the leaves turn black; but, if the ring should be of less width, death would not ensue, but, on the contrary, an accelerated growth, and greater fruitfulness, as in common ringing with the knife.

"I offer no theories, but I suggest that diligent observation shall be directed to the state of the branches in early spring, when the juices are in active circulation, and the limbs have been subjected to the alternate action of sharp frost and hot sun. The first thing is to ascertain in what the disease consists. If it is a fermentation of the sap destroying the vital connection between the bark and the alburnum, making, in effect, an extensive girdling of the tree, or of the body of the limbs, we may then search for the cause. I begin to fear that the cause is beyond cure. The pear tree shows its foliage early; and the most thrifty and succulent kinds are apt to be attacked with the blight. The early activity of the fluids, and the redundancy of them, may be greater in some years than in others, and if, at such times, unusual and severe alternations of heat and cold supervene, the effect may be to produce death in the larger limbs, and even in the upper part of the trunks of young trees, vitiating the sap, and causing it to decay. Persons at all familiar with the process of deadening trees in clearing forest lands, know that, even when entirely girdled, (cut round with an axe,) some kinds will continue to grow and maintain their verdure the whole season; and some will even put forth leaves the second year, and then die. In the same way, the branches of the pear tree will expand their foliage, and make thrifty shoots, being a mere development of the buds by means of the juices laid up in the branches; and, when that supply is exhausted, they become blighted at the extremity, and so proceed downward until the marks of death extend to the lowest point of disease, just as the green trunks of young trees, driven into the ground as stakes, will throw out shoots which grow for several months, and then wither and dry up as if by blight."