Growing grapevines in Missouri requires special care. Missouri falls within the USDA hardiness zones 6b through 4b. This means that in winter, temperatures in parts of Missouri may dip as low as minus 25 degrees F. Low winter temperatures can result in trunk injury and crown gall infection. Additionally, unexpected late-spring frosts can injure flowers and reduce fruit yield. The key to growing grapevines in Missouri is in carefully selecting grapes and properly maintaining them.
Plant the grapevines on the southern slope of a hillside or the south side of a windbreak, such as a house or fence, to provide warm temperatures and full sunlight needed to ripen fruit.
Erect support trellises at the end of each grapevine row by sinking fence posts into the end of each row. Stretch 9-gauge wire between each fence post at heights of 36 inches from the ground and 60 inches from the ground.
Amend the soil as soon as it can be worked in the spring. Improve heavy clay soil with gypsum if the planting site is in southern Missouri. Improve the soil in northern Missouri by adding finished compost. Plow over the entire field.
Plant the vines early spring once the danger of frost has passed.
Dig a planting hole below the arbor that is large enough to spread out the plant's roots. Prune away any damaged or diseased roots. Place the root ball into the hole and cover it with soil. Firm the soil around the roots, leaving a slight depression to make watering easier.
Prune away all but the strongest vine. Stake the vine so that it will grow upright onto the trellis. Space the grapevines 9 feet apart on the trellis.
Pinch out the tip of the vine when it reaches the top of the trellis to encourage side shoots to develop. Prune away all but the strongest two side shoots.
Mulch around the base of your plants with straw. Pull weeds by hand or cultivate no more than a 2 to 3 inches inches deep to avoid damaging the roots.
Prune the grapevines each spring to encourage fruit production.