This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
If we were asked to say what practice, founded on principle, had been most beneficially introduced into our horticulture - we should answer mulching - mulching suggested by the need of moisture in our dry climate, and the difficulty of preserving it about the roots of plants. - A, J. Downing.
At the late meeting of the American Pomological Convention the subject of mulching was brought up, and an opinion unfavorable to the practice prevailed among those who participated in the discussion. As there was no vote taken on the question, it would be unfair to conclude that the sense of the meeting was opposed to the practice, as might be inferred from the published reports of. their proceedings.
It is perhaps to be regretted that the Convention should undertake the discussion of such subjects, its time being too limited to do them justice; otherwise we can hardly conceive it possible that a practice so generally conceded as being in the highest degree beneficial, should be branded as injurious, at least without some explanatory qualifications.
The object of mulching is to maintain a uniform degree of moisture in the soil by arresting surface evaporation. This is most effectually secured by the interposition of a stratum of air in repose. Bodies are said to be good or bad conductors just as they are solid or porous.
Iron is a better conductor than wood; granite stone a better conductor than brick. Hard pressed soil is a better conductor than soil that is loose and porous. A beaten path is warmer in summer and colder in winter than the cultivated ground alongside of it; its particles being in close contact, its conducting powers are increased; the arid winds of summer passing over its surface carries off the moisture which the heat evaporates, and renders it unable to support healthy and vigorous vegetation; therefore in covering with manure, tan, or charcoal dust we apply a material that contains more air than the soil, and in a position not easily disturbed.
As to the value of mulching as an auxiliary to successful culture, the result of practical experiments fully confirms all that theory propounds; and in the case of newly planted trees the preservation of a uniform degree of moisture in the soil surrounding their roots is the most important point of management, and, other things being equal, trees will languish or grow just in proportion as this condition is secured.
One of the speakers at the Convention alluded to, observed that, "mulching had always proved of no value, but rather injurious. I have found that the mulch dries out in summer when most needed, so as to be of little value, and the trees cast their leaves." This might well be taken as an argument in favor of mulching, as the trees lose their leaves when the mulching fails. The evident course, to pursue in such cases, would be to renew the mulch and so maintain vigor and preserve the foliage. The drying out of the mulch is no argument against its value. Such materials as tan bark, wood chips, charcoal dust, or even barn yard manure does not readily dry out, or decay. It cannot be considered a fair test to allow the mulch to dry out "when most needed".
Another objection to mulching is the harbor it provides for mice and insects. When mulching has been left on during winter I have seen much destruction from mice eating the bark and roots, but I have never seen mice do injury to trees in clean, cultivated ground, whether mulched or not; and in regard to insects I would express a contrary opinion, and assert that were it convenient to keep the soil constantly covered with a suitable mulch, we would abridge, to a considerable extent, the increase of insects; the shade and moisture of the mulching being inimical to their habits.
A further objection was brought forward, "that a' heavy mulch absorbs all the water from a light shower, and the soil below is dry." This, as an objection, is practically unimportant.
Although mulching is apparently a simple operation, yet care is required in its application. Before mulching a newly planted tree, if in the spring, shape the soil in the form of a basin, extending the rim beyond the extremities of the roots, thus rains will be retained and artificial waterings effectually applied, if found necessary. If planted in the fall, the soil should be mounded slightly to the stem and well firmed round the roots; in either case be careful that the mulch does not approach nearer than within 10 or 12 inches of the stem of the tree. Winter mulching should be heavy to prevent frosts from reaching the roots, and will be found of great benefit in clean ground, but if rough and weedy so as to encourage mice, no mulching should be applied during winter, and every precaution taken to prevent them from eating the bark, such as trampling around the roots after heavy snows, and keeping the soil well pulverized, clean and compressed.
To be effectual it is not necessary that the mulching in summer be heavy, three or four inches in thickness of well rotted manure I consider the best that can be applied; if tan or charcoal dust, a thickness of two inches is sufficient; the short grass cuttings of the lawn forms a very suitable material, but it must be spread thinly so as not to ferment, which it is very sure to do if applied wet in quantities; a mouldiness frequently originates after fermentation ceases which is very injurious. Some years ago my attention was directed to a plantation of young trees that had suddenly and prematurely lost their foliage. They had been carelessly mulched with rough hay, and it was discovered that a peculiar fungus had originated in it and spread over the roots, and in some cases enveloped the stem of the tree. The mulching was immediately removed and the soil forked over; the growth of the fungus was arrested, but several of the trees died. I mention this as a warning to inexperienced midehers.
The benefits of mulching may be carried into the vegetable as well as the fruit garden. Mulching between the rows of growing crops I have found to be of great value. The soil is not compressed by rains nor baked into a crust by sun, weeds are kept down, evaporation arrested, and the crops materially increased.