Grapes are much easier to grow than most people imagine, but do be prepared for the vines to be hard taskmasters ! Pruning is essential and sometimes when growth is rapid this can take up much time.
Grape vine cultivation
Vines can be grown both indoors and out-doors. They can be grown successfully provided certain simple rules are observed. Success depends on well-prepared fertile soil, healthy plants of reliable varieties, simple pruning and training and, where outdoor varieties are concerned, warm sheltered positions where the grapes can ripen properly in late summer
- These prefer a warm, sunny position and are usually grown best in the southern half of England rather than in the north.
- Choose a deep, well-drained fertile soil and plant at any time from mid-October to February, choosing plants purchased from the nursery-man, grown from vine eyes or cuttings.
- Plant firmly and immediately after planting, prune the young plant to within 12 inches from its base to encourage a strong shoot to grow.
- Plants out of doors can be grown as cordons, espaliers, fans or bushes.
- The bush method is the simplest and consists mainly in cutting the branches of the plant back each year to within 1 inch of the main stem. The straggly habit of the brush form makes it a nuisance in the garden and the berries may be spoilt by trailing on the ground.
- The cordon is the most common form. It consists of a rod trained to a wire framework about 4 feet high. The rod is encouraged to grow in the same way as an indoor plant.
- The laterals from the rod are trained 12-15 inches apart and cut back each winter to one bud. Horizontal cordons can also be grown and these have the advantage that they can be covered with tall cloches in late summer to help to ripen the berries.
- Espaliers are grown by developing pairs of branches 12 inches apart from the main stem. Two- or three-tier espaliers are quite sufficient.
- Fan shapes can be grown quite easily by training 5-8 shoots from the main stem to grow on a wire framework.
- The general pruning treatment is the same as for indoor plants, but of course, much less growth will be made during the summer months. In August, cut away as many of the side shoots as possible, so that light and air will get to the berries and ripen them properly.
- Planting distances for the various types are: Cordons, 3 feet apart; Espaliers, 6 feet; Fans, 8 feet; Horizontal cordons, 4 feet.
- Each winter give the soil round the plant a dressing of good general fertiliser, together with a mulch of farmyard manure. Once again prune in November.
- Vines can be propagated by eyes or cuttings. Cuttings should be 12 inches long and inserted to half their length in good soil in November or December. Vine eyes can be propagated in a greenhouse or warm place.
- Vines are self-fertile and there is no problem with pollination.
Vines in a mixed house
It is possible to grow good crops of vines with other plants. Plants or creepers must not be allowed to grow along the rods and obstruct light but, of course, those plants which must have a good deal of light will suffer during the summer.
- Shady conditions, however, suit such plants as ferns, begonias, fuchsias, gloxinias and are not too unfavourable for perpetual carnations, pelargoniums, and some cacti and other succulents.
- Tomatoes are not a good crop to grow under vines, since they require more light and a drier atmosphere than the vine.
Vines in pots
Some gardeners grow vines in pots, and apart from being plunged out of doors during the autumn and winter, their general treatment is the same as that recommended for vines growing indoors though, of course, the rod is kept very much shorter and grown in an up-right fashion. The rod may be no more than 3-4 feet long.
The best aspect for a greenhouse in which a vine is to be grown is one facing south, but there is no reason why other aspects should not be successful, as has often been proved. Span-roofed, three-quarter span and lean-to greenhouses will produce good crops, as well as house porches. The important thing is that the vine plant should get as much sun as possible, especially during the summer and early autumn. Many of the best varieties of vines do best in a heated greenhouse, but there is a wide enough selection to choose from when no heat is available.
If some heating is installed, it is an advantage to have some means of keeping the atmosphere moist during the growing season by syringeing the plants and soil underneath them frequently — at least once a day. It is not a good practice to spray water on hot water pipes as this may result in scorching the young foliage and grapes.
The soil in which the vine plants are to be grown should be as fertile as possible. Where the soil is naturally deep and loamy it may only be necessary to dig in some well-rotted farmyard manure or compost before planting the young vines. Where the soil is not suitable, it is an advantage to remove it, or at least part of it and put in fresh soil. Old turves which have been weathered for a year or two and allowed to rot down partially, make an excellent foundation for this purpose. Good drain-age is also important; vines will not grow well where there is water-logging at any time. The soil should also contain a certain amount of lime and this can be sprinkled over the surface at the rate of ½ lb. per square yard while the border is being prepared. If the soil is heavy e.g. clay, drainage can be improved by digging in coarse gravel, or sand as well as organic matter such as peat. Basic slag at 1 lb. Per square yard will also help to improve the texture. Potash is also needed for vines and this can be added in the first case by sprinkling wood ash or burnt garden rubbish over the surface, again while the border is being prepared. Basic slag, as above, supplies phosphates for good root action, but bonemeal can be used instead and this will also supply nitrogen. 1 lb. Of bone meal per square yard forked into the surface soil will help. Where the soil is light or gravelly, organic matter will help to retain moisture and many gardeners find it an advantage to mulch the surface of the soil with compost or peat during the growing season. A layer 2 inches deep over the surface will help to cut down loss of water and reduce the need for frequent watering. This mulching should be done each year.
Most gardeners buy their vine plants from a nurseryman and these can be planted at almost any time of the year, since they are grown in pots. The best time, however, is in late October or early November. Young plants which have been grown from eyes or cuttings and are well rooted can be planted at the same time. Where the vines are received in pots it is advisable to break the pot, otherwise you may damage the roots when taking them out. When lifting young plants from the open border, lift as much soil as possible round the roots. The reason for early planting in autumn is that the plants are pruned at that time so as to avoid damage from bleeding which takes place when pruning is carried out in late winter and early spring. Should bleeding occur, it can be stopped by binding the cut shoot with painter’s knotting.
- Soil in the border and round the plant should be moist before planting. Do not set the roots too deeply in the soil; the depth of planting should preferably be that at which they were originally grown in the nursery or pot.
- Generally speaking, vines are best grown with one main stem, when the plants should be set out not less than 4 feet apart. This allows the laterals to grow 2 feet in length. Where vine plants are grown with several stems the distance between these must not be less than 4 feet.
- Dig a hole wide enough to take the roots spread to their fullest extent. If the soil round the roots appears to be unsatisfactory remove as much as possible. Allow 18 inches from the wall of the green-house. A 6 foot cane placed beside each plant will give all the necessary support for the leading shoot and side-shoots for the first year.
In the spring following planting, young shoots will develop. When these have made six leaves remove the growing point from all except the leading one which will form the rod, and all sub-laterals should be stopped above the first leaf. This treatment should be continued during the summer months, but when the leading shoot has grown 6 feet, the growing point should be taken out and all side-shoots pinched above the first leaf, except the top one which will then be allowed to grow on during the summer Should this existing shoot grow more than 6 feet, another cane can be tied to the cross wires which are fixed to the beams across the length of the house, so as to carry any extension of growth of the rod. A well-grown young vine may reach the roof of the greenhouse by the end of the summer.
When the leaves fall in early November, winter pruning may be done. The leading shoot or rod is cut back to 3-4 feet from the base according to its vigour. All side-shoots growing from this rod are cut right back to their base. During the winter no heat is necessary, otherwise this may cause bleeding of the vine by encouraging the sap to flow. During the winter also, the opportunity can be taken to put up any special framework on the roof of the green-house. No. 8 gauge wire stretched along the length or side of the house and spaced 12 inches apart will give satisfactory support for the vine rod and side-shoots during the following years. Canes can be tied to this wire framework for the first 3-4 years, depending on the size of the greenhouse, to support the young tender shoots.
In a heated greenhouse, vines can be started into growth in February. Start off with a temperature of 45°F (7°C) raising this by the end of the third week to 60°F (16°C).
Don’t allow the temperature to rise above 65°F (18°C) on sunny days, when ventilation should be used. When the buds break, rub out the weakest one, leaving one only on each side-shoot base. After these buds grow out into new lateral shoots and a bunch of fruit has set, the lateral should be stopped by pinching the shoot at the second leaf past the bunch. During this time the leading shoot will be growing and making new side-shoots which should be shortened as already described in the work for the first year. Side-shoots from the rod can be tied to the wire framework with raffia. Should bleeding of the wounds result from pruning, cover the cut surfaces either with a vine styptic or seal with a red-hot iron or cover with a layer of sealing wax. Provided the soil is in reasonably good condition all that should be required is top-dressing of well-rotted manure when the vines are starting into growth or a dressing of bone meal at 4-8 oz per square yard given over the border. In addition, one of the special vine fertilisers may be used, applied according to the manufacturers’ instructions in April. During the summer months ventilate the greenhouse adequately and at the first sign of mildew on the leaves, spray with thiram to control.
Vines in unheated greenhouses should not be started into growth until March or early April and the same care should be taken in regard to feeding, ventilation and spraying.
Sufficient water must also be given to moisten the soil thoroughly, though where the roots are allowed to grow outside the house there may be less need for this than where the roots are growing inside. Mulching with organic matter will help to reduce the need for watering.
At the end of the growing season – August, early September – less ventilation should be given, so that warmth will help to ripen the grapes. Remove surplus shoots, so that light gets to the berries.
When the main rod has reached the top of the house it should be pruned each year, the leading shoot removed completely and all laterals on the main rod pruned back to one or two eyes during the dormant periods. Space out the laterals on spurs so that these are not less than 12 inches apart. After a few years the spurs become large and should be reduced in length as much as possible. Occasionally, these old spurs will put out a young growth from near their base and they can be cut back to this point.