Rensselaer Union, Volume 7, Number 4, Rensselaer, Jasper County, 15 October 1874 — Importance of Tap Roots. [ARTICLE]

Importance of Tap Roots.

It is a habit of trees and some vines to send down a strong and large tap root directly beneath the body of the tree. If that was not essential to the well being of the tree the tap root would not be formed. “ W,” in Cultivator and Country Gentleman, states that seedling pear trees always, and seedling grapevines generally, have vertical roots which thrust deeply downward and supply the leaves with the necessary cqld water through the severest droughts. But as these get older, and especially if grown from sprouts or layer?, we find the roots directed horizontally, and then, if they are in open, dry, unsheltered soil, a fewsummers will disease them so that the leaves become open to blight and mildew and winter finishes what the trials of the summer time had weakened. It is a difficult problem in tree culture to constantly secure a sufficiency of moisture in the soil, and at the same time to encourage the roots to run deeply. A wide mulching of the surface will retain moisture indeed, but it infallibly attracts the roots to grow and feed close under the mulch, within the grip of either drought or frost when the mulch has decayed away. Thorough draining and deepening of soil not naturally well drained, and either a constantly mellow or open surface, or a constantly close-cropped sward of grass, are most favorable to healthy and regular root supply. English books and practice advise the suppression of tap root. It is an established principle in their arboriculture that these should be checked and horizontal roots encouraged as much as possible. In planting Wall trees in gardens they sometimes lay an impervious pavement down in the soil under the trees as a precaution against the dreaded canker of the stem. We follow this lead. Our nurserymen find that a tree transplants better for having many small roots, disposed to run through the rich surface soil, rather than two or three vertical prongs. But it is very doubtful whether there is substantial advantage in this course, applied in our hot, dry climate, for we hnd that trees in forests and along fences, which have “ come by chance,” and have never feft steel in their roots, either of pruningknifeor pfrsw, will maintain heafth~andSroductiveness. to an extreme old age. [ursery-grown trees, cultivated in orchards, sicken every few years after severe vicissitudes of weather, and perish prematurely. Even where the subsoil is impervious hard-pan all around, so that there is no drainage, we find the selfplanted tree enduring, although its roots are all necessarily horizontal, because they cannot penetrate the hard-pan, or if they do they are pinched off by the poisonous nature of the subsoil, or drowned off by the water which is held all the year near the surface. In such soils the forest trees—which are apt to be blown over in storms because they are only standing on the hardpan and not anchored in it—show, when uprooted, a perfectly flat mesh of horizontal roots. A tree with this form of roots will not live long in rich, well-drained soil in our climate—evidently because it is irregularly supplied. It is all feast or famine with it —repletion or drought. After a rain the growth is suddenly inordinate, and again in our frequent summer droughts even the roots are dried. Soon the stems begin to decay, owing to these alternations, and then the tree irretrievably declines.—A. F. Herald.