Walks and talks of an American farmer in England (Part 2 of 2)

DECAY OF VARIETIES.—TWO THEORIES: KNIGHT’S, DOWNING’S.—ENGLISH THEORY AND PRACTICE.—PRACTICAL DEDUCTIONS.—CAUSES OF DECAY.—REMEDIES.—HINTS TO ORCHARDISTS.—SPECIAL MANURES.—PRUNING.—THOROUGH DRAINAGE.—A SATIRICAL SKETCH.—SHOOTING THE APPLE-TREE.

It is known that many varieties of apples, which fifty years ago were held in high esteem as healthy, hardy sorts, bearing abundantly very superior fruit, have now but a very poor reputation, and varieties which a hundred years ago were highly valued and extensively cultivated, are now extinct. It is believed, too, that the most celebrated old varieties that are yet cultivated, are much more subject to canker than others; or, in other words, that trees of these varieties are more easily affected by unfavourable circumstances, or have a more delicate constitution.

To account for this, there are two theories held by different scientific horticulturists. The first—which originated with the late Mr. Knight, a distinguished vegetable physiologist of England, who devoted much attention to the subject, and made a long series of experiments upon it—may be stated as follows:

Each seedling tree has a natural limit to its life, and within that will have a period of vigour, succeeded by a natural and inevitable decline, corresponding to the gradually increasing feebleness which attends the latter part of the natural life of a man. And all trees also which have been propagated from such a seedling by means of buds or grafts, or, in other words, all trees of the same variety, are to be considered as merely extensions of that seedling, and will have a cotemporary vigour and decline and decease with it. The period of vigour or decline may be much extended by circumstances favourable to the general health of any particular tree, and by unfavourable influences it may be shortened: but however well situated, sooner or later it will manifest feebleness by the change in the quality of its fruit, the small quantity it is able to bear, by the decay of branches, and especially by its liability to be attacked by diseases, such as the canker, which rapidly destroy its remaining vitality. These diseases may be guarded against, and may often be cured; but the longer the period since the origin of the variety from a seed, the greater the liability and the more difficult the cure.⁠[2]

This theory is entirely discredited by other distinguished botanists and horticulturists, among whom are Dr. Lindley in England, Decandolle on the Continent, and Mr. Downing and H. W. Beecher in America.

These consider that there is no such similarity between the life of a tree and the life of an animal, and that a bud and a seed contain equally the germ of new life, that they are, in fact, the same thing, except that they are prepared to be developed under different circumstances. That each bud, twig, and branch, has a life of its own, and the trunk is but an association of roots, or of connections between each bud and its roots. It may be separated from this trunk as a seed is, and will continue to live if ingrafted upon another trunk, where it will connect itself again with the ground and grow, and through it other independent lives will be produced and sustained. Or it may be removed from its parent and placed upon the ground, where it will make roots and extend and reproduce again as independently, in all respects, as a seed. It is held that the death of trees does not arise from any natural period being assigned to their existence, but that the tissues of a tree, as they grow old, become dry and hard; no longer transmit sap, lose their vitality and gradually decay; yet the process of growth may continually be renewed exteriorly to this death, so that large cavities will often exist in the interior of trees. As, however, the peculiar natural food of the tree within the limits to which it can extend its roots, becomes exhausted, or, as other unhealthy circumstances affect it, its vital power and its re-vitalizing power will be diminished, and finally may become extinct.

If, however, a bud or germ of a new branch can be taken from the tree before its decay, or from any part of it that yet retains its vigour and health, and be transplanted by means of cuttings in the earth, or inoculations or grafts upon another healthy stock of the same species, it will have all the vital energy, and, in every respect, all the natural character, of a seedling.

In explanation of the general deterioration of certain favourite old varieties, according to the theory of Downing and Lindley, their state should be compared (taking care not to run the analogy too far into the ground) to what is popularly understood as a scrofulous condition of human beings, rather than to the decrepitude of old age. From various causes—want of proper food, unfavourable climate, propagation upon unhealthy stocks, high feeding, and any unnatural stimulus producing imperfect succulent growth, and from constant repropagation from trees that have in a greater or less degree so suffered—the trees of the variety have very generally lost their natural, strong, active, resisting, and recuperative vital energy, and have a general tendency to disease, which will be developed in different forms according to circumstances. A wound upon a scrofulous subject is more difficult to heal; exertion produces more fatigue, and rest brings less return of strength. Food, which in its natural state would be most nourishing and healthful, it can no longer digest, and it does it more harm than good; exposure to cold, to malaria, or contagion, is more dangerous, and if it escapes all acute disease it gradually grows more and more feeble until finally it has “died of a decline.”

Sterility attends the decrepitude of age, but not the scrofulous debility in man, neither does it the degeneracy of the old trees. But the scrofulous habit is hereditary in man; so it is believed to be in the old varieties. If, however, the scrofulous inheritance is not very virulent, by a judicious course of regimen it may be gradually overcome, and a strong vigorous constitution once more re-established. So it is argued, and facts are cited that seem to sustain the position, may the old varieties be restored to their pristine excellence, by care to select scions from the most healthy trees, and from the most vigorous parts of them, and to propagate these under the most favourable circumstance for their healthy growth.

The predisposition to disease in these ill-treated trees may result in a contagious malady, and this may spread beyond them and attack trees of ordinarily good constitution, and in the most salubrious situations, though, of course, the liability of these to take the malady, and their recuperative power under its attack, will be proportionate to their strength and soundness. The disease known as the yellows, in peach-trees, seems to be of this nature.

There are many facts unfavourable to both these theories, and many phenomena which neither of them, in my opinion, satisfactorily explain. The popular judgment in England seemed to have accepted Knight’s hypothesis. But while every body was mourning over the degeneracy of old favourites, the utter neglect or miserable mismanagement of their orchards seemed to me to bear strong testimony to the correctness of the contrary theory.

The practical deduction, it may be remarked, from either view, does not greatly differ. By judicious management, the health, vigour, and profit of a fruit-tree, which would otherwise, after a certain time, pine away and die, may be greatly extended, if not made permanent; and trees which are already failing from decrepitude or disease, may be restored. On the other hand, if trees are planted in unhealthy positions, insufficiently supplied with those materials that are necessary to the formation of strong, compact wood; if they are cruelly mutilated, crowded too close together, &c., they will not only be feeble and unproductive, but will be particularly liable to the attacks of vermin, disease, and parasites, and, in their weak condition, will soon yield their life to these enemies. Moreover, the insects which are bred in them will extend their ravages to surrounding trees, the seeds from their parasites will be scattered over the neighbourhood, and the disease which is generated in them may be indefinitely extended among their species.

The most common causes of disease, decay, and decline of a fruit-tree, which it is in the power of the orchardist, in a great degree, to control, are these: the exhaustion from the soil of those materials which are its necessary food; the attacks of vermin, and the growth of moss or parasites; the loss of large limbs or other severe wounds; too great exposure of the trunks to the sun; too rapid and succulent growth from the stimulus of heat or exciting manures; and an impervious subsoil, which will allow water frequently to stagnate about its roots, producing what is commonly called by farmers “a cold, sour soil.”

Some of my readers, who have not studied the subject, may be glad to have me concisely indicate the most approved means of avoiding or counteracting these dangers.

Manures should be applied to orchards frequently and in moderate quantities, rather than in heavy supplies at distant intervals; and, to avoid unhealthy stimulation, they should be well decomposed. The best ordinary manure in the United States has been found to be a mixture of dung with an equal quantity of peat or black swamp-earth, chip-dirt, or rotten wood or leaves; and it is better that this compost should be mixed some time (the longer the better) before it is applied.

But, in addition, I have shown from the English experience that the apple-tree requires a more than ordinary supply of lime, (say a peck of air-slaked stone or shell lime to each tree, every year.) In the same way the pear is known to require especially potash, iron, and phosphorus.

Iron is found in sufficient quantity in most clay soils; where needed it may be supplied by scattering bog-ore, (found generally underlying swamps in America,) or iron filings, or the sweepings and scoriæ from forges. One pound of crude potash dissolved in water and poured over the compost manure, or half-a-bushel of wood ashes, to a tree, will be a good yearly allowance of potash; and half-a-peck of bones to a tree will supply the phosphorus. For the plum and the quince, salt is found particularly useful, and ashes for the peach. But let it not be forgotten that the apple cannot live on lime alone, nor the peach on potash, only that it is a special supply of these that they more particularly require.⁠[3]

The Herefordshire orchards suffer much more from moss, parasites, and insects, and less pains are taken to guard against them or to destroy them than is usual in New England. There is a fine moss that will not easily be detected, that often collects upon the branches, and, diverting the juices of the tree to its own nourishment, eventually, if not removed, destroys the bark; and limbs are seen frequently thus denuded of their natural defence, and the wood consequently decaying. This is doubtless a common cause of organic disease. The ordinary preventive and remedy for every thing of this sort is to wash the trunk and principal limbs of the tree every year with a weak lye—in which it is a good plan to put a little sulphur—all insects having a particular repugnance to it.⁠[4] If there is much dead, scaly bark, it should be first rubbed or scraped off.

Trees should be allowed to branch low and naturally. The “trimming up” and unnatural exposure to the sun of the trunk of the pear-tree is known to particularly predispose it to a most fatal malady. Where trees are properly managed while young, it will never be necessary to prune their limbs in our climate; and there can scarcely ever be a case where the cutting off a limb larger than a man’s arm will not be likely to do more harm than good. Wherever it is done, or wherever a large branch has been blown off, the stump should be squared off neatly, and a salve of clay and cow-dung spread over it and secured upon it by a cap of canvas or sheet-lead. Smaller stumps should be covered with paint, or with a coating of shellac dissolved in alcohol.

Too rapid and succulent growth, making imperfectly formed wood, through which the future processes of the growth of the tree or the fruit formation will be inefficiently performed, is occasioned either by too stimulating food in the soil, or by a forcing heat in the climate which excites a growth unnatural to the original habit of the tree. There are also probably other yet unexplained causes for it. The preventive must be determined by the cause. The immediate remedy is shortening-in with a knife one-quarter or one-half of the growth of each year. This is absolutely necessary to the successful cultivation of the peach in many situations in the United States, and, as I have shown, is sometimes used as a remedy for canker in the apple-tree in England.⁠[5]

Too retentive a subsoil, or a cold, sour, malarious bed for the roots of an orchard, is only to be remedied by under-draining. Mr. Thompson, of the London Horticultural Society, gives a striking instance of the profit which may attend this operation.

Having detailed several experiments, he remarks that “want of drainage deprives the roots of proper nourishment, subjects them to a chilling temperature, and forces them to absorb a vitiated fluid.” He then describes an orchard planted, in 1828, upon a retentive marly clay. He says, “the trees grew tolerably well for some time; but after seven years they began to exhibit symptoms of ill thriving, and were every year getting worse: I saw them in 1840, and instead of increasing in size they seemed to be decreasing.” The trees grew worse, and the following year several died. It was then determined to drain the land: 3000 feet of draining-tile were laid, 3 feet deep, in parallel lines, 48 feet apart. In the spring of 1843, and in the autumn of the same year, 3000 feet of drain pipes, 1¼ inch bore, were laid at 30 inches deep, so that the drains were then only 24 feet apart; the ground at the same time was dug over eight inches deep, and the trees pruned. The following year the proprietor writes: “I never housed any thing like 50 bushels before; now there are at least 75 bushels, while my summer fruit was at least double the usual quantity.” Upon this, Mr. Thompson remarks:— “The lopping-in of the trees and digging the ground, as above described, were doubtless advantageous proceedings; but the draining of the ground was unquestionably the main cause of the extraordinary change in the condition of the trees; for stunted specimens, that previous to the draining were covered with moss, had made no shoots for years, and were in such a state of decrepitude that there was nothing to cut away but dead wood; these had produced vigorous shoots when I saw them in 1847, and have continued to do so up to the present time. Such vigour cannot be attributed to the cutting-in, for in these cases it was not practised; nor to the digging of the ground, for although this was done before draining was thought of, yet the trees went backwards, the decay of their branches increased under all circumstances till 1843, when recourse was had to draining, and since then they have continued to do well, producing vigorous shoots—shoots upwards of three feet in length; and in the present season the fruit was abundant, large, and highly coloured.”

A case was mentioned before the Staten Island Farmer’s Club, in 1850, of an under-drain having been run near two greengage plum-trees, which had previously been for many years entirely barren; the year after, without any other operation upon them, they bore bushels of fruit.

The following satirical sketch of the management of the Devonshire orchards, contains an amusing account of the ceremony of “shooting at the apple-tree,” before alluded to.⁠[6]