This section is from the book "The Gardener V1", 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.
It is difficult to understand on what natural or physiological principle the aeration of Vine-borders is either beneficial or necessary; we suspect the whole thing is a misnomer, and that it is simply drainage. We should like it explained on what principle a current of air filtering through a border, if it really does so, is beneficial to the roots; certainly we have nothing of the sort in any of nature's fruit-borders. We hold that the soil should be firm and compact about the roots of all fruit-bearing trees and plants, let it be Apricots, Pears, or Pines, and Strawberries, and even our Vine-borders, provided the soil composing them be of the proper mechanical texture; we abhor, of all things, to be potching in our Vine-borders, and a compact soil is incompatible with aeration, but not with drainage. What is called aeration we conceive would be of great benefit in a damp and dropsical climate, where the borders would readily get saturated and soapy under the influence of heavy rain-fall. But what would be said to "aerated" borders on a gravelly soil on the east coast, or even thoroughly-drained borders on any bottom, where, as a rule, much artificial watering is necessary? We know from abundance of experience that aeration, such as is found beneficial on the dripping west coast, would be a long way worse than useless on the droughty east coast, especially on light and naturally dry soils.
Last season, in spite of mulching and all the watering we were able to apply, our borders got aerated very much more than we liked. Indeed, mulching, and especially watering, is a very heavy item of our labour, and we know from experience over more than one place on the west coast that such is superfluous. Large Grapes (we mean berries) are the result of plenty of feeding, either naturally through the medium of rain in a rich border, or by the artificial application of liquid in some other form. No doubt there are cases where, from the position of the borders naturally or artificially placed, aeration and heating would be almost a necessity - as, for instance, at Welbeck, where the borders are curiously sunk so low beneath the general surface out of reach of the sun's rays, and in an inland and elevated locality where the rainfall is abundant; but that only points more clearly to the superior arrangement of having the borders entirely above the surface and unheated, as at Garston. We are told that heated borders must be successful if well managed, and if they fail it must be the fault of the gardener. The bulk of the finest Grapes in the country are grown in unheated borders.
We would incline to reverse the above charge, and say that the gardener who could not grow good Grapes without the questionable assistance of pipes for bottom-heat, had something to learn or unlearn. Inside borders for very early and very late Grapes are proved to be sufficient when well managed, for the Vine does not really require a high degree of heat at the root. For summer and autumn Grapes the outside border being elevated is also sufficient, which no one will dispute; but the elevation is rather to secure dryness in the border in autumn than for the advantage supposed to be derived from higher temperature.
One word about temperature in the atmosphere of the vinery. If the Vine is supplied with a steady and abundant supply of food and moisture at the root, a high indoor temperature is most beneficial, but it must be attended with free circulation of air. If the Vine is a gross feeder, it has also a wonderful digestion, and under high pressure will store up an amazing amount of stamina for future produce. That it will ripen its fruit sometimes in favoured parts of England, does not prove that it also ripens its wood sufficient to withstand, say a Crimean winter. What is the summer temperature of Malaga, or of the valley of Jericho, where the spies found the large clusters, or the borders of the Caspian? we suspect our vineries seldom approach those localities in their aggregate of summer heat or even moisture. And yet the Vine is not a tropical plant. We never could exactly understand putting the Vine to rest, or ripening its wood by exposing its branches to our summer and autumn weather. We may stop its growth by cold, but that is not putting a Vine to rest; and we suspect that is at the bottom of early-forced Vines starting prematurely in autumn.
We find those Vines which go to rest with their wood matured with strong heat, have the least tendency to start prematurely; indeed, are the slowest to move under forcing. But if the Vine has lost its foliage through red-spider or any other cause, it is hopeless to put it to rest by the high-temperature process. Recourse, under these circumstances, must be had to cool treatment and a short supply of fruit the following season. The Squire's Gardener.