Trellising and vine training
Vines can be trained over a pergola or a post-and-wire trellis. To begin this process, vines should be trained up a garden stake, bamboo stake or something similar. It is important during the first year to let the vine grow vigorously to achieve the desired height. This will allow the vine to establish a strong root system and framework (e.g. the trunk and arms of the vine). Only one single shoot should be trained throughout the first growing season; select two to three shoots initially, and remove all others. Tie the two to three shoots to the garden stake with string or plastic tape (flagging tape/budding tape). Once one of the shoots reaches 0.5-1.0 m in length, remove the other shoots, leaving the favoured shoot. Remove the lateral shoots that emerge at the base of each leaf. Do not remove the leaves during the growing season, these leaves will supply the vine with the food they require for the next growing season.
If the vines fail to reach the desired height in the first year, the shoot (now redish-brown in colour and called a mature cane) should be cut back in winter, to two to four buds above the beginning of it's growth point. Repeat this training process again in the second year. If the vine establishes well in the first year, it will start producing bunches in the second year. A couple of bunches can be left to ripen if desired. We don't want to overload (stress) the young vine with fruit at this stage of it's life, as this will stunt it's growth for future years.
Watering and fertilising
Watering regimes will vary depending on where you are growing your vines. For the Perth region, regular watering of vines in the home garden is necessary from early November to late March in most seasons. Applying mulch will help retain moisture in the soil during summer months. Mulch can be placed all around and touching the trunk without risk of encouraging disease. Disease risk is minimised if the water can be kept off the foliage.
A mature vine will require about 500g of NPK fertiliser with trace elements each season. This should be applied as a 350g dressing at or near the start of budburst and a 150g dressing four weeks later.
Pruning
There are two basic methods of pruning table grapes, these are spur pruning and cane pruning. If you are in the Perth region, pruning is best carried out in late August, however pruning can be done anytime after the leaves have turned yellow or the leaves have fallen. In regions where the temperature is not cold enough to induce leaf fall (e.g. the Gascoyne), vines should be pruned mid July.
Spur pruning is used on highly fruitful varieties such as flame seedless, italia, muscat grodo and cardinal. These varieties produce one or two bunches on every shoot every year.
Cane pruning is used on low fruitful varieties such as sultana, dawn seedless, red globe and crimson seedless. These varieties only carry bunches on less than half the shoots that emerge after pruning. If the name of the variety of grape is unknown, the best pruning method is to have a combination of spurs and canes until the fruitfulness of the vine can be determined.
Spur pruning
*Photo of spur pruning*
Highly fruitful varieties that can be spur pruned only have bunches in the first 2-4 buds on each cane. How many spurs that will be left after pruning will depend on whether the vine is on a pergola or a post and wire trellis. If the vine is growing on a pergola, then 20-40 spurs can be left. If the vine is on a post and wire trellis then 16-20 spurs will be sufficient.
These spurs are shortened lengths of the previous season’s shoot growth and should be spaced 10–20cm apart on the permanent arms of the vine. Each spur should be two or three buds long which will produce a maximum of two new shoots in the spring.
The most common fault with pruning vines in the home garden is overcrowding of spurs.
Cane pruning
*photo of cane pruning*
Varieties that need to be cane pruned carry bunches on the previous season’s growth towards the end of the cane. There are very few bunches to be found in the first four buds along each cane. These varieties require 6 to 12 canes at the end of pruning. Each cane will have 8 to 16 buds, but be no longer than 75cm. These canes are tied onto the wires of the trellis for support.