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.
Crops of Grapes from pot-Vines, we need not say, have now more than ever become common. Hence the enormous quantity of Vines prepared for the purpose in all the principal nursery establishments in the kingdom, to say nothing of the numbers prepared by gardeners for their own use. Many gardeners produce their earliest crops from pot-Vines exclusively, and the practice has much to recommend it; and chief among these recommendations is the fact that no one set of permanent Vines can bear the murderous strain which ripening their crops in April entails upon them. True, we have known the same Vines to have borne ripe crops in April for twenty years in succession with their roots exclusively in outside borders; but this is the exception, not the rule. And in consequence, many of our very best Grape-growers are adopting the judicious practice of getting their first spring crops from pot-Vines. The success of this practice, it need scarcely be said, depends more on the way in which the Vines are prepared than on all else besides. First and foremost among the points of importance in their preparation is, that they be grown under the influence of plenty of light, so that they have well-developed buds and well-ripened wood and roots.
Strength must be regarded as of importance, but not unless the former condition can be secured at the same time. On this account we have always had a decided objection to Vines that have either been grown under the shade of permanent Vines, or too thickly in an upright position in the centre of houses devoted entirely to themselves, under which circumstances sound and fruitful growths, though strong, cannot be produced; and we would advise growers to avoid such conditions.
There is another practice connected with fruiting Vines in pots upon which too much stress can scarcely be laid, and that is the allowing them to grow and ramble to the length of say 8 feet, and then to shorten them back to 5 or 6 feet when they are pruned. The consequence of this is, that all the best and most fruitful buds are removed and the more inferior retained. The length to which the Vines are required to fruit should be decided when the Vines are being prepared, and all cutting back avoided as an evil. We would not advance an objection to an 8-feet Vine, but we have no hesitation in saying that in forcing a Vine of that length to ripen in April the far finest crop will be from the top half of it; and it will be best to acknowledge this in fruiting it, and to let it bear its fruit exclusively from the top half, which will not only break first, but show and swell the largest and best bunches - just because of the fact that the best buds are there, and that the flow of sap is principally to them instead of to the buds and shoots lower down. Now, to shorten back such a Vine to nearly half its length is to remove those buds where their whole energies have been directed during the previous and preparative year's growth.
True, a Vine with say six or eight bunches on the top half of its length does not perhaps look so systematic, but the finest produce is nevertheless thus attainable; and this is the chief test of practice in Grape and all fruit culture. We would, therefore, say to all beginners of pot Grape-growing, do not shorten back your Vines if they are well ripened up to their tops.
It has long been a common practice to set their pots on beds of earth, or to turn the Vines entirely out of their pots into such beds with the idea of feeding them. We have doubts as to the correctness of this theory or practice. Certainly the finest pot-Vine-grown Grapes we have ever seen had their pots standing on a bare shelf. It is always certain that whatever feeding is afforded to Vines having their roots entirely within the limits of the pots in which they were prepared, they are sure to get the direct and immediate benefit of. Not so when their roots are allowed to leave their pots and ramble at will in a bed of soil. Any additions which it is desirable to make should be in the shape of top-dressings, and these should never be piled up high over the pots and pressed to the stems of the Vines in their early stages of forcing, or the result is that the Vines make a whorl of roots from their stems, and the roots in the pots are much more shy in commencing their work.
These remarks may be suggestive to some of our readers, and we shall be very glad to have the experience of the more practised in this now very important auxiliary in Grape-growing.
I Do not think that any one can doubt the correctness, in the main, of the very able article on this subject in the last number of the ' Gardener.' If I would have any objections upon any part of it, it is in the third paragraph, where the writer has his doubts about the correctness of allowing the roots to get in any way out of the pots in which they have been grown. It seems to me that a Vine that has been grown, and prepared for fruiting, in a pot - the Vine is such a strong feeder - must, in most cases, to a great extent have taken the chief of the so-called substance from the soil. And this is not all, for in many gardens where there is a host of other things to be looked after, and labour is not over-plentiful, I do think that - it seems a natural advantage - they would be better to have their roots so that they would not be kept so strictly to their pots. But on this subject I will go no further.
I have had three different lots of fruiting pot-Vines this year, and any one could see at a glance the truth of the sentence, that more depends upon "the way in which the Vines have been prepared, than all else besides; " for it is not by any means the largest and best-looking that have proved themselves to be the best. No doubt, size is a great advantage if it is otherwise supplemented; but without that, it is better to give way to one a little less strong and otherwise well matured.
But many of your readers must have observed, if not experienced, the difficulty that there is in getting up a good lot of pot-Vines in some places compared with others. At some places they will grow away like willows, quickly and strongly; whereas in other places, with the greatest care, they can hardly be got to make a fair start at all. At least such is my little experience. I have some very good ones this year, struck in February, and grown on in an old Pine-stove, without any more than usual attention, and they have quite satisfied me (I send you a sample); whereas with, I believe, greater care at a former time in a different place, I have failed to get up a first-rate cane; and even two-year-olds (cut-backs) were not so good as one-year-old Vines here. This is not new, but it shows something.
Before concluding these remarks, I will just state what I intend doing with a lean-to vinery of a moderate size soon. I intend to plant it next year with young permanent Vines, but before doing so I want to get out of it a crop from pot-Vines. I will place a row of pots at the usual distance apart along the front of the house; then on a stage of boxes and planks I will have another row about halfway up the house. From these I will almost get as many Grapes, I hope, as from an ordinary house of permanent Vines, for the roof will be almost all covered by these two rows. I will have the crop off, then, in time for planting a fresh lot, to get their growths up to the top of the house the same year. This year I planted a house in June, and some time ago they had reached the top of the house. They have done well, but it is the soil that has done it; for I am a firm believer in the passage that "Paul may plant and Apollos may water," but we must have our increase from another source. Robert Mackellar.
[The sample of young Vine sent is moderately strong, and ripened to a solid hard hazelly brown, with very little pith - such Vine-wood as may be relied upon. There is scarcely anything in horticulture more remarkable than the influence of different soils in Grape-growing. - Ed].