The Best Time to Trim Grape Vines

When to Trim

• Trim grape vines in the early to late winter while they are still dormant. Grapes pruned in the early winter bleed less, but are susceptible to winter injury. Gardeners who trim grapes at the end of the winter encourage grape bleeding. Bleeding sap will not harm grape vines, but cold injury reduces yields or may even kill off the grape vine. To prevent cold injury, prune in the late winter months. Also, your region's winter temperatures play a part in determining the best time to prune.

Regions

• Those living in regions such as Iowa that experience cold winters may prune anytime between March and early April, according to the Iowa State University. Gardeners living in southern regions that receive moderate winter temperatures must prune right before their grapes come out of dormancy or before the last frost. Furthermore, gardeners in southern regions typically grow Muscadines grapes, because of their warm climate. Prune these grapes in the fall after the first frost, as suggested by the National Gardening Association.

Planting

• Trim grapes in the spring at the time of planting. Grape vines must experience a full growing season before they are strong enough to survive cold winter temperatures. Prune off all unhealthy areas of the grape vines and roots. Healthy root should not exhibit any dark mushy areas. The top growth should be trimmed down to one healthy cane, according to Ohio State University. Pick one cane that looks the strongest and is producing healthy growth.

Trimming

• Trim off 90 percent of the wood produced the previous season off your grape vine, as suggested by Oregon State University. Pick four canes and trim them back, so that 15 buds remain on canes. If you are growing grapes for wine, leave five buds on each cane. Those growing table grapes should leave 12 buds per a cane. Pruning your grape vines helps plants produce a higher quality crop, because their energy goes to fewer buds.