Grapevines are a popular addition to the home garden. Not only do they provide delicious fruit but also give good summer shade when trained over screens and pergolas. Fruit is borne on the current year’s wood and regular annual pruning will encourage new growth. They are easy to grow, preferring a sunny, well-drained position.
A grapevine will grow up and over a pergola even with little training but unfortunately it won’t necessarily grow how you want nor be very productive. Training the vine will ensure it grows where you want and the fruit production will be optimal. If room permits consider planting different varieties of grapes (spaced at 2 ½ - 3metres apart at support). This will provide a choice of grapes over the harvest period.
1. Plant your vine approximately 30cm from the base of post or support.
2. During the first summer the vine is planted, choose the strongest shoot and attach this to the support of pergola. Remove all other growth.
3. The following winter, when vine is dormant, prune back the main stem by approximately half its length to wood that is at least pencil thickness. Remove any lateral growth.
4. During the following summer, again choose the strongest upright shoot as a trunk and attach this to the post and remove all other shoots.
5. Once the vine has grown and reached the top of the pergola, trim the leading cane. This will cause new shoots to grow from the buds immediately below the cut. Select 2-4 of these shoots to provide a framework to cover the pergola.
6. The following season, thin out shoots that develop off the main arms, leaving about 15-20cm in between shoots. Attach and train these shoots to cover the required area.
7. Once the final shape is established, all lateral shoots off the main arms are annually spur or cane pruned. For information on spur and cane pruning go to Our Gardening Corner.
The fruiting buds of grapevines are borne on one-year-old wood which arises from two-year-old wood. Water shoots, which grow on wood older than two years, do not bear fruit. A heavy pruning of up to 90% of the last season’s growth is required each winter while the vine is dormant.
Whilst the majority of table grapes are spur pruned, some grapes such as Sultana require cane pruning. This is because they do not produce enough fruitful canes when spur pruned. Therefore a number of long canes are left to ensure a good crop. For more information on pruning grapevines go to Our Gardening Corner.
IMMEDIATELY after pruning spray with Lime Sulfur and follow 3-4 weeks later with Copper Oxychloride. This ensures a good winter clean up of your vine, killing any bugs and fungus that harbour along the stems, thus minimizing re-infestation of pests and diseases. Feed in early spring (Aug/Sep) with Richgro Fruit & Citrus fertilizer and an application of Sulphate of Potash.
Grapes require regularly watering throughout their growing season. Ideally water around the base of plant or by drip irrigation. Avoiding the use of overhead sprinklers will help to prevent the onset of fungal disease.
Grapevines are susceptible to downy mildew. This can be controlled by spraying with Copper Oxychloride when new shoots are approximately 20cm long. Apply at 14-21 day intervals but do not apply during flowering.
Thin in early summer by removing some developing clusters. This will encourage the remaining clusters to grow larger and produce bigger fruit. This also increases the hardiness of your vines.
For more tips and information visit Our Gardening Corner.