How to Grow Grapes Outside

Plant your desired variety of grapevines in well-draining soil with a pH of 5.0 to 6.0 in spring, when the danger of frost is over and the soil is workable. Ensure the planting site is exposed to full sun. Space multiple grapevines 8 feet apart in a row, with rows 10 feet apart.

Cut the strongest cane of each grapevine down to three buds immediately after planting. The buds will eventually develop into canes on the plant. Clip off and discard the remaining canes of each plant.

Water the grapevines every week, providing 1 inch of water with a soaker hose. To reduce the chances of fungal diseases, irrigate the plants at soil level. Avoid over-watering grapevines or causing pools of water around their base.

Apply a 2-inch layer of organic mulch over the base of each grapevine to insulate the soil, suppress weed growth, and retain soil moisture. Use organic mulch such as wood chips, grass clippings, dried leaves or wood bark. Space the mulch several inches from the grapevine stem to prevent rot.

Feed each grapevine 1 to 1.5 lbs. of high-nitrogen (10-6-4) fertilizer every year in early spring, before the plant produces new growth. Spread fertilizer granules on the ground around the plant, 6 inches from the stem. Alternatively, provide each row of grapevines 10 lbs. of 10-6-4 fertilizer per 100 square feet of area.

Insert a 4-foot stake behind each individual plant soon after planting. To encourage vertical growth, attach each plant's growing tendrils to the stake behind it with lengths of elastic cord or nylon cloth.

Replace the stakes with 7-foot wooden posts when the grapevines reach the top of the stakes. Insert each post 10 to 12 inches into the soil. Run two parallel lengths of wire along the posts in the row, spaced 36 inches and 60 inches above the ground. Pull the wires taut before securing them to each post with galvanized staples.

Train each grapevine to grow and spread along the wires for maximum sunlight exposure and air circulation. Clip the shoots of each grapevine down to three buds along the lower wire. Secure the shoots to the wire with elastic ties. Clip off shoots that grow between the two wires.