This section is from the book "The Gardener's Monthly And Horticulturist V23", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
Let us take a glance at what is termed annual aerial rootlets, and investigate the theory, and see if they are only annual and aerial. Not a few may consider it a piece of vanity in hesitating to believe that upon which acknowledged authorities have agreed. But when we consider how many hypotheses have been overthrown, that stood good for many years, we are justified in picking to pieces that which has been pronounced complete, as regards the office and turn of annual rootlets. I am reluctant to accept any cause or effect in nature as being spontaneous, and not coming under the great law that governs all. I refer to the explanation given in the Monthly that rootlets, by way of chance, or by their own will, became true feeding roots by meeting here and there accidentally privileges which were denied others, or through reluctance not taken advantage of. Before going into the philosophy of this subject, I wish to call attention to a few points that may help to avoid misunderstandings. It is not a good idea to subject an example for experiment to unnatural conditions or habits, and glean from it results to verify a theory, as it is too apt to do the reverse, and only damages the cause.
As regards plants, when wanting to experiment on them, their natural habit and position should first be ascertained, and know that every family of plants has a separate office to fill in nature, and that nature has designed it for one purpose only. That man turns it to different purposes, has nothing to do with what nature created it for.
In my opinion all vines that twine or cling are among the most dangerous enemies to trees, and designed by nature to destroy them by robbing them of light and air. Through the twining nature of many the ascend of sap is greatly obstructed, which in time will cause the tree to decline, and if not yet a tree prevent it from ever becoming one. This is the office and nature of the Wistaria, and not to creep upon the ground. Such vines as cling to objects by means of rootlets, cannot be said to be to any degree dependent on them for existence, but undoubtedly assist those in the earth to a greater extent than is known. One importance more, and that as much as any may be attributed to them, which is, that the rapidity of growth is due to the firm hold and support that they lend to the vine. To illustrate clearly, those who may not be aware of the importance of a firm support for vines, if rapid growth is desired, may take for an example two Smilax vines, each to a cord, one drawn tightly and the other allowed to be slack, and the importance of tightly drawn cords for vines will manifest itself.
That these rootlets die every season does not prove that they are annuals and only aerial, as they decidedly gainsay this when put into favorable conditions, where they will send them into the earth and become roots for good. That they die every season proves two facts; first, that they are premature and wither in consequence of not finding accommodations, but still obey the edict of nature by holding the vine firmly to the object they chose to cling to; secondly, the sequel of these rootlets dying is to furnish accommodations for roots in time. When attached to a wall or rock this accumulation of decomposed vegetable matter incited through the action of frost will in time reduce them to earth, their mission there being analogous to Lichens; but when to a tree, the vine with its rootlets becomes a dangerous enemy, not alone in excluding the stem from the action of light and air, through the accumulation of dead rootlets and leaves, but also by its encouraging all kinds of insects to harbor there, and with their assistance kill the tree by inches.
In place of the undeveloped and crippled roots, that till then appeared to be aerial and annual, a new set of roots, as the tree gradually decays, will grow out and be roots in earnest, and send them into the rotten woods.
[There is so much of bold free thought in Mr. Poppey's papers, that they are no doubt read by most of our intelligent readers with great interest. It seems, however, but right to say that many of the positions assumed are untenable. For instance that a vine injures a tree by "excluding from the stem the action of light and air." If it injure, it cannot in that way. It is a well-known fact that a tree trunk may be encased with earth up to its branches, not only with no injury, but with actual benefit. This was all there was in the celebrated Bolmar method of treating fruit trees which excited so much interest about Cincinnati a quarter of a century ago. - Ed. G. M.]