This section is from the book "The Gardener's Monthly And Horticulturist V20", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
Some time during the past season I read an extract from the pen of one of our savans - Prof. Winchell, I believe, on the above subject, which, if I remember correctly, teaches doctrine at variance with the facts of the case. The position of the professor, as 1 now remember it, is that the treeless condition of the prairies of the "West is caused by the physical condition of the soil composing this part of the country. I understand the article referred to teaches that a very finely pulverized soil is not congenial to tree growth; that a coarse soil, with more or less rocks and gravel, is essential to the growth of timber. The Western prairies being composed of very finely comminuted soil, are uncongenial, and, indeed, detrimental to arboreous growth. Assuming that I have correctly understood and remembered the meaning of the author - for I have not the article now before me, I object to the teaching of the theory for the following reasons: First - a soil of fine texture is not necessarily unfriendly to tree growth. There is no finer soil in the world than some of the clay soils of Indiana and Ohio where timber grows, and has for ages grown luxuriantly. Second - it is not true that all the soils of the prairies is of the fine tilth represented.
It is true that a large part of prairie soil is of vegetable origin, and of course this is generally finely comminuted, but there are extensive districts where rocks and gravel abound, and they are yet as destitute of timber as other parts. Portions of Kansas are as rocky as the hills of New England, and yet are without timber. True, in some cases, the summit of rocky hills is crowned with timber, that it is only where the grass grows so scant that the annual fires can never reach them. Third - timber is found growing in ravines, and, especially, on the borders of streams, out of the reach of fire, but where the soil is as fine in texture as can be found anywhere. Fourth - it is not true that timber will not grow in the soil of our prairies. The millions of trees now growing luxuriantly in all the settled portions of the prairies in a sufficient refutation of the assertion. I have been, all my life, familiar with timber growth, having grown up in intimate acquaintance with the forests of Indiana; but I never saw, in that State, timber grow with the rapidity and luxuriance that it does here, on these vast plains.
Seedling trees set at one year old often grow from five to seven feet the first year, and some kinds often make a growth of eight to twelve feet in height, and one to one and one-half inches in diameter, in a single season, after being established. Does this look as though the soil of these piraries is too fine for timber to grow ? I think not Lastly - the soil of the Western prairies is as various and diverse in both physical texture and chemical constituents as that of any other part of our country; therefore, whatever may be the cause of their treeless condition, it is clearly not attributable to the fineness of the soil. The cause of this distinction is, I think, clearly found in the annual burnings that consume the grass and with it all incipient tree growth. That this is the cause is evident from the two following considerations: First - it is abundantly adequate to produce such a result. All over these plains the fires have been accustomed to sweep every year from time immemorial. These fires when driven through the dry grass before a strong breeze such as generally prevails during the season that this burning takes place, are almost resistless.
These flames, when going fairly with the wind, often travel with the speed of a race horse, leaping sometimes 100 feet or more at a single bound. No small timber can stand before such fires. A second evidence that this the true explanation of the absence of timber is the fact that, whenever the fires are kept out for a few years a spontaneous growth of timber comes in and takes possession. All over these prairies are straggling shrubs and seedling trees that want only immunity from these destructive fires to spring up and produce groves and forests.