How to Grow Grape Vines in Illinois

Find a location for growing grapes that is in a warm, sunny, well-drained location. The majority of Illinois vineyards are located in the southern portion of the state. Grape vineyards typically plant grape vines on the southern side of a hill where they will receive the most sunlight and warmth in a day and will not have waterlogged soil. Grapes need warm temperatures and exposure to sunlight to ripen.

Use a variety of grape that is compatible with the USDA hardiness zone of your region. Illinois stretches across USDA hardiness zones 4 through 6. The state experiences lows that do not get below minus 5 degrees Fahrenheit in winter in zone 6, but will drop down to minus 25 degrees in zone 4. Popular grape varieties for Illinois in addition to Improved Chancellor are Chambourcin, Vignoles, Seyval, Vidal and Norton.

Erect trellises in rows crossing the slope of the hillside. Grapes are commonly grown in a two-cordon system in which the trellises resemble fences with two wires. One wire should be located 4 feet from the ground. A second wire should be located 6 feet from the ground. The grape vines will grow against these wires for support.

Plant grape vines beneath your trellises as soon as the ground is warm enough to be worked. Grape vines should be spaced approximately 8 feet apart in trellis rows. Dig a planting hole beneath the trellis and place the roots of the grape vine into the planting hole. Each hole should be large enough to spread out grapevine roots without bending them. Set the top of the grape vine root ball level with the soil line of the plant and cover with soil. Remove all of the vines from the plant except the single healthiest-looking vine.

Sink a bamboo stake into the soil behind the grape vine. Tie the grape vine to the stake so that the vine is erect. Allow the grape vine to grow up the stake until it reaches the top of the trellis. Remove any side shoots. When the vine reaches the top of the trellis, remove the stake and tie the plant to the trellis. Pinch out the tip of the vine and allow four side shoots to develop. Tie each shoot to one of the trellis wires.

Overwinter tender grape plants during cold Illinois winters by pruning them back to the main trunk and untying them from the trellis in fall. Bend the trunk down to the soil and cover it with 6 to 8 inches of soil or mulch. Uncover as soon as the frost is off the ground and lift the vine back onto the trellis. Tie shoots to the trellis as soon as they develop.

Taste grapes before harvesting to gauge sweetness. Grapes change color long before ripening and may still be sour even after the grapes change color. Harvest grape clusters when the grapes are sweet.