Watering Once established, grapevines are very drought tolerant but benefit from deep watering as plants regain their leaves during extended dry periods. Too much water as the grapes ripen can cause fruit to split.
Feeding and mulching Feed in late winter or early spring through the growing season by applying a complete fertiliser for fruiting plants such as Seasol plus Nutrient Fruit & Citrus. Supplement with a liquid fertiliser such as PowerFeed PRO SERIES Fruit & Citrus every 2 to 4 weeks during the growing period (spring to autumn). Mulch under vines and keep the area clear of grass and weeds.
Pruning Prune fruiting grapes in winter, cutting back long growth. In the early years after planting, train the vine to its desired height and encourage it to form a framework of horizontal growth. The general rule once the framework is established is that each winter the previous year’s growth, some 90 per cent of the plant, is cut back to the established horizontal framework. Some varieties have more specific pruning needs, it is important to check on the correct pruning method for the variety you are growing.
Watch out Many pests attack grapevines fruit from caterpillars that chew newly opened leaves to birds that peck at the ripening grapes. Large pests such as birds are managed by using exclusion methods such as bird-safe netting over vines or bagging of fruit clusters.
Insect pests may require physical intervention. The caterpillars of grapevine hawkmoth and grapevine moth can skeletonise leaves and defoliate a vine. They can be removed by hand or sprayed with an organic pest control such as EarthCare Enviro Pest Oil insect spray.
Grape leaf blister mite and grape leaf rust mite are microscopic insects that cause blistering damage on leaves. Although the vine may look tatty its fruit will not be affected. To control mites, remove affected leaves and make a note to spray in late winter, after pruning with Sharp Shooter Lime Sulphur.
Downy mildew is a fungal disease that attacks leaves causing brown, yellow or red patches on the top of the leaf with patches of white downy growth on the underside. Remove affected growth and use preventative control in winter by applying Sharp Shooter Lime Sulphur.