This section is from the book "Commercial Gardening Vol3", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
Presuming the style of house to be decided upon, and the building finished, the preparation of the borders should next receive attention. It has already been impressed upon the reader that commercial grape growing of to-day will not bear the extra cost of growing where the soil is not naturally suitable. However, there are cases where a grower may wish to put up a few vineries to supply a local demand, and in such a case it may pay him to go to the extra expense of preparing an unsuitable soil; therefore in dealing with the subject of border preparation this will be taken into account. To take the good situation first. Except in rare cases it will be necessary to provide some system of border drainage, and it may be necessary to lay a drain outside the houses as well, e.g. when the land is on the slope and natural drainage not very free it will be found in wet winters that there will be considerable soakage from the higher ground, sufficient to keep the borders of the houses wet on the uphill side. In such a case a drain should be laid to intercept this flow; and to make sure that the drain shall work well and rapidly the trench should be filled up with clinker till the porous top soil is reached. Thus the borders will be more under the control of the grower. Unless the soil is too wet to be suitable for grapes, the inside of the house will only require one line of drain to each border, i.e. a 15-ft.-wide house would have two drains running the length of the house, a 25-ft. house four, and a 30-ft. house six. These drains should be put 3 ft. deep, and should discharge into a larger main drain running along outside the lower end of the houses.
This being done, the preparation of the borders for the Vines may proceed. Digging two spits deep should be all the mechanical preparation a good soil should require; but unless the soil has a good supply of lime in it a heavy dressing of ground chalk must be worked in. In chalking land it is common practice to apply as much as 10 tons to the acre. This amount applied to a greenhouse border works out at 140 lb. per rod, or a little over 4 1/2 lb. per square yard. This quantity may be spread over the surface or be thrown on the soil as it is turned up. When digging, the top soil is usually kept to the top, the bottom spit being merely turned over and broken up. When the trenching is done, a good dressing of old hot-bed manure or any well-rotted manure should be pricked into the surface soil, and at the same time a dressing of some good complete artificial manure may be given. The borders should then receive a good watering and be left to settle down.
It is always advisable to get an analysis of the soil when taking a fresh place; expert advice as to the manure actually required can then be obtained. Many growers when making up their borders use a great quantity of bone meal. This manure certainly forms a lasting supply of phosphates for the roots to draw upon. The famous pastures of Cheshire were made fertile chiefly through the large dressings of coarse bone applied to them years ago; 1 ton or more per acre of roughly broken bone would be spread on the land and rolled in. This quantity works out at 8 oz. per square yard, and if the grower intends to apply it it can be spread on the surface before the trenching is begun, bone meal being used instead of the broken bone.
Now with regard to the preparation required where the situation is not really suitable. Supposing that there is a thin soil of only about a spit depth above a stiff retentive clay, or a subsoil full of water which would be unhealthy for the roots to run in. In such a case the best possible thing to do would be to build the walls of the houses high enough to allow 2 ft. of extra soil to be put on the borders. Readers must bear in mind that these directions only apply to the extreme cases mentioned; unless unlimited soil was obtainable it could not be done on a large scale.
Before bringing in the extra soil the borders should be taken one at a time, the soil thrown out to the depth of 1 ft., and a drain laid right down the length of the house, and then the whole bottom of the excavation covered with clinker to the depth of 3 in. The top soil is then returned, chalk and bone meal being thrown over it beforehand. Each border is treated in the same way and the drains taken off into a main as already described. When the whole house has been prepared in this way the extra soil can be wheeled in and spread and dressed as before. Provided the soil is available, this is not such an expensive business as it may appear; for drain pipes cost little and clinkers can be obtained at most destructor works for 6d. per cartload, and also from gasworks, though the price may vary a little. At some destructors the clinkers may be had for the carting away. Vine borders formed in this way will be under the complete control of the grower, and should be both warmer and drier than those formed on a level with the soil.
Reverting to the ordinary procedure, it is usual only to prepare the back borders the first year, and the remaining borders the second and third year till the middle is reached. In this way freshly prepared soil is available for the young roots till they occupy the whole space under glass.
Although for market work it is more usual to provide only inside borders, there are some growers who make outside borders as well. For mid-season grapes this works well if the land for the purpose can be spared; but for early or very late work the inside borders are best, because the watering is under control and the borders are warmer, which is especially important for early work.