As a profitable wall or fence coverer, a grape vine is worthy of consideration. Any one of the outdoor varieties is capable of producing many fine bunches of fruit. The plants are so hardy they resist any frost, and growth is brisk and vigorous against a warm, sunny fence or wall.
Warmth and sun are essential to ripen the fruit, so the fence or wall that is to support the plant, or plants, should face south, or south-east, or south-west; and not be shaded by trees or buildings.
Late summer should see the bunches nicely ripened and ready for use, of such outdoor varieties as Buckland Sweetwater (pale amber berries), Miller’s Burgundy (black), Reine Olga (reddish). and Royal Muscadine (white),
One of the most important points in soil preparation is good drainage. Ground that is waterlogged in winter, or after heavy rains at any time of year, can be put right by taking out a hole 6 ft. to 7 ft. long, 4 ft. wide and about 3 ft. deep, ramming 9 in. of broken brick, stone, or lumpy lime rubble into the oottom, then filling up with good garden soil. This will make a suitable bed for one vine.
If the soil is thin and dries out easily it will need to be stiffened by mixing with it chopped turves or a barrow-load of quite old manure. Rich soil is not wanted, but there must be adequate food in the ground.
A border at the foot of a house wall is not infrequently a mass of brickbats and other rubbish 1 ft. or so down. This will have to be made good to the depth of 3 ft.
When and How to Plant.
The best time to plant an outdoor grape vine is late October. Soil should be shaken from the roots (the plant will arrive from the nursery in a pot, or the nurseryman will have removed the pot and made a bundle of the roots) and these should be spread out in the planting hole; the latter to be of such a depth that when the hole is filled in, the roots are covered with about 4 in. of soil.
Soil should be worked between the spread-out roots with the fingers and made firm above and around them by treading.
If more than one vine is planted they should be not less than 4 ft. apart, grown as single main stems – that is, on the cordon principle. Or one vine can be made to cover a good deal of sideways space by training it.
Training a Cordon Vine.
The fence or wall needs to be covered with wooden trellis, or with horizontal wires spaced about 9 in. apart, to allow of the growths being tied back neatly and without any crowding.
The vine may be several feet long when received, a single rod or cane studded with buds. It is to be cut back to within 1 ft. of the soil. Given a warm summer, growth will be rapid. The cut-back rod will extend upwards, and side shoots will be trained out horizontally to left and right.
But not all side shoots are to be allowed to develop. The single-stem (cordon) vine is to be furnished with fruiting spurs on its left and right sides, 18 in. apart.
These are not to be in level pairs; each one is to be 9 in. lower (or higher) than its opposite side shoot. This arrangement enables all available space to be profitably covered without crowding.
Side shoots ‘in excess of the required number are to be rubbed off when quite small. Those that remain (at 18 in. apart each side) are allowed to grow full length, being tied back horizontally to the trellis or wire background as they extend.
At the end of the first full twelve months – that is, the following November – the tied-in side shoots are each to be cut back to within two buds of their base. Thus are the fruiting spurs formed. At the same time, the main stem is to be shortened to within about 4 ft. of the ground – that is, only 3 ft. of the summer’s growth is to remain. The young vine is now 4 ft. or so high, with a couple of fruiting spurs on its left and one – possibly two – on its right.
Each year the side growths from the established spurs will be cut back, and the main stem shortened so that not more than about 3 ft. of that summer’s upward extension growth is left to it. It thus increases its height each year by about 3 ft., until the top of the wall is reached, when no further extension growth is allowed. As its height increases, so more fruiting spurs are found room for at 18 in. apart on each side of the main stem.
A Horizontal-trained Vine.
The cordon vine is more suited to a house wall than to a low dividing wall or garden fence. Against either of the latter the cordon vine must of necessity be kept short. In these circumstances the horizontal-trained vine is more profitable in that left and right extension is encouraged and therefore a greater number of fruiting spurs can be produced.
For this system of training, a single rod or cane is planted, and cut down to within 1 ft. of the ground, exactly as is done with the vine which is to become a cordon. But no upward extension is allowed from the foot that remains. Instead,the two top buds are allowed to shoot and any others on the 12-in. stump are rubbed off. The two top shoots are trained out to left and right, respectively, to form horizontal main stems from which side shoots are allowed to grow up vertically at intervals of about 3 ft. These vertical side shoots become main stems. They are allowed to retain 3 ft. of the current season’s growth at each winter pruning, and fruiting spurs are formed on them at 18-in. intervals on their left and right sides. The two horizontal main stems are each also allowed to increase in length by about 3 ft. each year, which allows of the annual addition of one more fruiting rod (vertical main stem, each with its spurs) at the left and right extremities respectively. The sideways and upwards extension goes on until all available space has been filled.
Method of Fruiting.
Bunches of grapes are produced on young shoots which develop from the short spurs in spring; that is, the fruit is borne on shoots of the current year’s growth.
Pruning the Side Shoots.
The single side shoot from each spur is cut back each November or December, whether it fruited or not, to within two buds of the base of the past summer’s growth. The spur thus increases in length by not more than about in. each year.
All cutting should be done with a sharp knife, the blade directed away from the pruner, whose ether hand grips the rod firmly just below the point at which the cut is intended to be made.
When Spring Growth Starts.
Sometimes both buds left to a cutback spur will start into growth in spring; sometimes only one. A single shoot only is required from a spur, so if both grow one must be rubbed off when it is not more than about 2 in. long.
The tiny bunches of immature grapes, or rather flowers, can be seen when that much growth has been made. If only one of two shoots from a spur shows a bunch, that one will be left and the other rubbed off. If both shoots show a bunch,the stronger of the two will be left. If neither shows a bunch, the stronger shoot will be allowed to extend and the other be removed at once.
When the shoot with the bunch has extended and produced three leaves beyond the bunch, its end is nipped off so that only two leaves remain beyond the bunch. Side shoots produced by this stopped shoot are left with one leaf only; the stem of the small side shoot is nipped off just beyond this.
The spur shoot that shows no bunch should be allowed to extend to five leaves, the end then being nipped off.
Tying the Shoots.
The spur shoots need to be tied down or back to the trellis or wires, with raffia, when 9 in. to 12 in. long. The piece of raffia is passed around the shoot, near the outer end, then around the support and tied there. But as the shoot is very brittle at its base it cannot be brought to the horizontal position at once. It should be drawn only part of the way down (or back) at the first tying, and brought carefully to its final position some two or three days later,Pollinating the Flowers.
Outdoors, bees and other insects will distribute the pollen on which the set of fruit depends. But if insects do not appear to be visiting the vine in any number it is safer to brush the fully expanded greenish-white flowers with a small fluffy wad of dry cotton-wool, or a rabbit’s tail, tied to a stick or cane. This should be done when the sun is shining strongly on the vine and should be repeated over three or four days. This procedure is essential in the case of a greenhouse vine.
Thinning the Bunches.
If more than one bunch appears on a spur shoot the weaker should be removed. The remaining one needs all the nourishment it can get.
Thinning the Berries.
The berries are always thinned in the case of greenhouse vines, and this can be done outdoors if really first-class bunches of well-ripened berries are desired.
Thinning is done with long, thin, pointed scissors, and to avoid handling the berries – and rubbing off their bloom – ’the bunch is manipulated with the aid of a forked twig about 8 in. long, held in the left hand. The bare upper stem of the bunch is held in the crutch of the forked twig and thus steadied, or pushed sideways or forwards. First to be snipped out are berries in the centre of die bunch, then any very small ones on the outside, then any that crowd. The object is to leave berries spaced evenly at about in. apart all over the bunch. Thinning should start when berries are about the size of small peas.
The job is done most comfortably early in the day, before the sun is too strong, or in the cool of evening. A steady hand and much patience is required. Berries that are scratched with the point of the scissors will almost certainly decay, and bloom is all too easily removed if head, hand or sleeve rubs ever so lightly against them.
Thinnings need not be wasted. They make an excellent tart.
Watering and Feeding.
The border must never become dry, or berries may shrivel. A damp surface may be deceptive. To test the condition of the soil down below, push a stick 1 ft. or 18 in. into the ground, withdraw it, and examine the soil brought up on its tip. Repeat this here and there in the border. If water is needed, give several bucketfuls.
For feeding, when the berries begin to swell, one of the special vine fertilizers should be used; or poultry manure, a trowelful stirred vigorously into each bucket of water used. Or poultry manure may be mixed with an equal bulk of soil and spread over the border, subsequent waterings will carry the food down to the vine’s roots.
These are the greatest enemy of the outdoor vine. They can be dealt with as explained in the chart ‘Remedies Against Enemies of Fruit Crops’ –
Ripe bunches can be kept fresh until the end of the year if cut with about 9 in. of the shoot to which the stem of the bunch is attached. The piece of shoot is inserted in a narrow-necked bottle – a wine bottle serves well – containing fresh clear water, and the bottle is placed on a shelf so that the neck slopes upward at an angle of about 45 degrees, the bunch hanging clear. The bottle should be held in place with heavy books or anything else that will keep it steady and inclined at an angle. The water should be replaced with fresh, at intervals. Grapes thus dealt with keep best in a dark room, well ventilated and cool. Any berries that show signs of decay should be snipped out.
The grape vine can be increased by means of short lengths of side shoot, each length carrying a dormant bud. The method is explained under ‘ Grape Vine Cuttings’ in the section How TO PROPAGATE FRUIT TREES AND BUSHES.
Unheated Greenhouse Grapes.
Outdoor varieties grown in an unheated greenhouse or conservatory ripen some time in advance of those outdoors. The vine may be trained up the back wall, though a better position is parallel with the roof glass, with the growths tied to horizontal wires supported 18 in. below the glass. The vine may be planted outdoors and the main stem led into the greenhouse through a hole in the brickwork at the front. If the greenhouse is large and heated the border can be inside, and prepared as explained under ‘Preparing a
Greenhouse Border’ in the section FRUIT IN THE GREENHOUSE.
During the time that the indoor vine is dormant – in winter, when leafless – it needs all the fresh air it can get, ventilators being open except during frost. This must be remembered – for the sake of other plants that the same greenhouse may be required to accommodate in winter. Plants needing to be coddled will not be happy in those hardier conditions which die vine demands in winter.
Training the Indoor Vine.
The cordon system is most convenient under glass, a single rod being taken up until the limit of height is reached. At planting time the vine should be cut back to the point at which the front glass starts, or to within 1 ft. of the ground if planted against the back wall. Training, pruning and other details are then as explained in the case of the outdoor vine.
When growth starts in spring it may happen that the top buds on a rod push before the lower ones. In that case, to equalize growth, the rod should be untied and the top part allowed to hang down. That checks the upward flow of sap and encourages the lower buds to move; when the lower shoots are extending, the vine is tied upright again.
Ventilating and Syringing.
Warmth of the sun is trapped by careful manipulation of the ventilators. Before the sun goes off the greenhouse in the afternoon the vine, walls, glass and surroundings generally should be syringed with water of the same temperature as the house and the ventilators almost closed. The result is a sudden increase in temperature which will last throughout the night. The vine should also be syringed during the morning and the surroundings made damp, except during the time the vine is in flower and when the grapes are colouring.
Red Spider, Mealy Bug.
These pests can always be expected under glass. Treatment is as explained in the chart ‘Remedies Against Enemies of Fruit Crops’.
Leaf and Berry Troubles.
However dull and cold the weather might be there should always be sufficient ventilation given to keep the air inside the greenhouse on the move – without draughts, of course. If the sun comes out suddenly after a dull spell and the ventilators are almost closed, the foliage may scorch: that is, turn brown in places and shrivel. It happens perhaps most frequendy on early summer mornings, before the grower has increased the ventilation which was decreased for the night.
The same thing may happen to berries. Moisture deposited on these is suddenly dried up by the sun, and the berries are scalded. It does not happen if the atmosphere is moving, as it will be if the ventilators are open sufficiently.
Berries may split, or the stalks (shanks) of the berries shrivel, if watering is neglected for a time and the dry soil suddenly made sodden. Same results are experienced if the border is not properly drained, or if the vine carries a too heavy crop and is not being fed.
Preparing for Table.
The bunch of grapes should be placed (without unnecessary handling, to avoid rubbing off the attractive bloom) on a fruit dish lined with vine leaves – autumn-tinted if possible – with grape scissors by the side. As a food, grapes are as nourishing as they are delicious.