This section is from the book "The Gardener V3", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
If the position where the border has to be formed is naturally wet, a set of drains, about 10 feet apart, should be cut across it, and led into another drain running parallel with the border at its extremity; the latter should be a little deeper than the others; all should be cut at least 1 foot deep in the subsoil, and instead of using the soil cut out of the drains, for filling in over the pipes, wheel it away, and for this purpose use any of the following materials that can be most readily procured - brickbats, small stones, gravel, burnt shale, or chalk. The drain-pipes used should have close-fitting sockets, to prevent the roots of the Vines getting into them. When the drains are filled in is the time to consider whether the border is to be heated underneath by hot-water pipes or not, or if it is to be aerated. The former is quite unnecessary, unless for Vines that are to be forced very early. The latter is of importance wherever the soil is of a stiff retentive character, or where it may come under the designation of loam, but not sandy loam. For the latter we think it is of little or no importance whether the border is aerated or not. As far as known to us, we were amongst the first to recommend the aerating of Vine-borders from beneath.
We at the time considered it theoretically right to do so in circumstances such as indicated, and since then we have had ample proof of its practical value. It is most readily effected by laying a number of large drain-tiles all over the surface of the bottom of the border, connecting them by means of upright pipes, say 4 inches in diameter, with the external air at the extremity of the border, and with the atmosphere of the Vinery, by means of similar pipes, rising a few inches above the surface of the inside Vine-border when finished. The openings of the pipes inside the Vinery being in a higher temperature than those outside, a constant current of air will pass through the whole pipes under the border, from the external to the internal atmosphere of the Vinery, aerating the soil from beneath, - the effect of such aeration being, that the constant supply of oxygen from the fresh air will decompose the carbonaceous matter in the soil, convert it into carbonic acid gas, which, combined with water as its vehicle, enters into the roots of the Vines, ascends into their leaves, where, under the influence of light, it is decomposed in its turn, the oxygen liberated into the air, and the carbon fixed in the tissues of the plant.
In support of this theory we may state, that having repeatedly examined the state of the roots in borders formed on the principle in question, we have found the interstices amongst the pipes, and even in them, a complete mass of fine healthy fibrous feeding roots.
It may be objected that in very dry weather a current of dry air would injure the roots. We do not think so, if the border is kept properly watered; but during such weather the remedy is an easy one - plug the mouths of the pipes that come to the surface to supply air to the pipes underneath.
Having laid down the pipes to effect what we have just described, fill in around and over them with loose stones or brickbats; then lay a course of turf, with the grass side down, and on this wheel in the soil of the border, but do not wheel over the made-up border: throw it up as loosely as possible, so that it may have its interstices full of air, which will hasten the preparation of the various ingredients of which it is composed for food for the Vines; and generally such borders heat a little, which gives newly-planted Vines a rapid start by setting their roots into action at once. Another benefit resulting from this system of forming Vine-borders, is the facility with which superfluous water passes away, or can be detected if it does not by sounding the upright air-pipes. Where the soil of which the border is made is of a light sandy character, aeration is by no means necessary, for all carbonaceous matter in such soil is rapidly decomposed and prepared for the food of plants, from the facility with which air permeates it in all its parts.
In such cases, all that is necessary is to drain the subsoil of the border as directed, if it is naturally wet, and to lay a few inches of lime-rubbish over its surface, then turf and the soil on it.
The concreting of the bottoms of Vine-borders should only be resorted to where the subsoil is of a very bad character, such as irony gravel. If it is honest clay or pure gravel or sand, we would not concrete, but would rather endeavour by kindness to keep the roots near the surface of the border, as we hope to show when we come to write of Vines after they are planted.
We now come to consider the question of covering outside Vine-borders. This is generally done to effect one or other of three purposes: to prevent the radiation of the heat the border has derived from the autumn sun; to warm the border by the application of hot fermenting material to its surface, such as leaves and stable-manure; or to throw off heavy falls of rain during the winter.
Of the first of these we thoroughly approve, and to effect it nothing is more suitable than a few inches in depth of dry fern or leaves, covered with wooden shutters, laid so as to run the water to the front of the border and into the drain, which in all circumstances should be there.
To attempt to heat the border by the application of hot manure applied to its surface, we consider a mistake, though it is still persisted in by good Grape-growers. The only excuse we can accept for it is the absence of the more rational method of applying heat from beneath.
The importance to be attached to covering Vine-borders for the mere sake of throwing off superfluous rain, very much depends on the rainfall in the neighbourhood. In that from which we write, where it seldom exceeds 30 inches in the year, and where the subsoil is a dry porous gravel, there is no necessity for covering them for the mere sake of throwing off rain, nor have we ever covered any of the borders of houses where the Grapes hang in fine condition till the end of March, and even April; but the case is different in localities like Greenock, for instance, as well as other places that could be named, where three times the quantity falls in a year. In such situations, even with good drainage, it is desirable to cover the borders of houses where late Grapes are hanging, as soon as the autumn rains set in, for which purpose glass, boards, or tarpaulin may be used. We do not like the system of concreting the surface of Vine-borders in order to accomplish this end, which was brought into notice by writers in the 'Gardeners' Chronicle ' some twenty years ago, for the reason that it in great measure excludes the beneficial influence of the air from the soil, which cannot safely be dispensed with, whether in the flower-pot or the Vine-border. Gardeners are familiar with the term "sour" when applied to soil, and which means nothing more than that it has got its particles so compactly forced together, when wet, that there are no interstices betwixt them into which the air can force itself and exert its "sweetening" influence; hence the importance of aerating Vine-borders by artificial means, where the soil of which they are formed is at all approaching an adhesive character.
(To be continued).