Grapevines are rustic, fruit plants that grow in the long summer seasons of warm areas. The most widely grown commercial crop in the world, grape plants may live for up to 50 years. They require loose, quick-draining soil, full sunshine and air movement to thrive. Their long vines require support structures for healthy growth and exposure. If you have a pergola, plant grapevines at the posts and train them to grow up over the roof.
Plant grapevines in spring, after the last frost lifts. These are sensitive plants that do best with a warm-weather start. Wait for nighttime temperatures of 15.6 to 18.3 degrees Celsius (60 to 65 degrees Fahrenheit).
Set out one grapevine per pole. Each vine requires adequate space for root and foliage growth. If poles sit in light shade to sun, count on the vines to grow upward for their required sun exposure. If poles sit in deep shade, skip them; the grapes won't thrive without light. Mark planting sites 15 to 30 cm (6 to 12 inches) from the poles and 30 to 60 cm (1 to 2 feet) wide.
Amend and build up soil in the planting sites. Dig with a garden spade into the top 25 cm (10 inches) of natural soil to loosen it, pulling out rocks and weeds. Add 10 cm (4 inches) of organic compost for quick drainage, rich nutrition and good moisture retention; mix well. If the site drains slowly or tends to puddle in winter, add 17.5 to 20 cm (7 to 8 inches) of organic compost to build up the soil level and increase drainage rates.
Plant grapevines in holes as deep and wide as their root balls, in amended soil. Fill amended soil in carefully around the roots to keep out air pockets, then supply 1.9 litres (1/2 gallon) of water to settle the planting. Prune each grapevine down to two to three healthy buds for future growth.
Screw eyehooks into the poles of the pergola at every 30 cm (1 foot), moving toward the roof. Tie the grapevines to these hooks as they grow to train them upward.
Feed grapevines with 10-10-10 granular fertiliser one week after planting, at a rate of 227g (8 oz) per plant. Sprinkle the fertiliser in a circle around each vine, 15 cm (6 inches) from the trunk, and turn over the top 7.5 cm (3 inches) of soil. Give each vine 5 cm (2 inches) of water immediately after the feeding, and put them on a schedule of 5 cm (2 inches) of water every week.
Mulch a 5 cm (2 foot) circle around each grapevine to keep soil moist, warm and free of weeds. Grapevines fail in dry or crowded soil.
Prune grapevines every year if you want fruit harvest. Limit pruning if you want decorative growth rather than fruiting. Increase fertiliser for grapes to 453 g (1 lb) of 10-10-10 granular fertiliser in the spring of the second year and 680 g (1 1/2 lb) every spring thereafter. Give grapevines new compost amendments every spring to maintain soil quality and drainage.