Grape Pruning for Home Gardeners

Learning Objectives

• Understand the purpose of pruning grapevines

• Identify parts of a grapevine

• Explore when and how to prune new and established grapevines for maximum fruit productivity

Grapes in the Home Garden

Grapes are a unique fruit crop that can offer fruit growth at home and add a new plant layer to garden landscaping. Because grapes are botanically classified as vines, they grow and are established differently from other fruits like trees, shrubs, and brambles. 

Grapes can grow on a variety of structures. You may see grapes on a trellis, a pergola structure, grown like a fan on the side of a building, or growing unmanaged. Pruning is an important management technique that maintains vine shape, supports higher yields and produces better-quality fruit. An unmanaged grapevine will appear tangled, disorganized and will not be optimized for fruit production. In contrast, the anatomy of a managed grapevine will have a clearer structure and is pruned to maximize grape production.

Grapevine anatomy

Understanding the parts of a grapevine will help direct and guide your pruning, making it easier and less intimidating for beginners. Familiarity with grapevine anatomy will inform your pruning cuts. A grapevine’s primary structures include the trunk, cordons, canes, shoots, spurs, nodes and buds.

Click the hotspots on the image below and watch the video for additional information about grapevine anatomy.

Preparing to Prune

Grapevines require annual pruning to maximize fruit production. The best time to prune grapevines is while they are dormant, in late winter or early spring, before buds begin to form shoots. Dormant pruning consists of removing or cutting back younger wood (canes) or older woody structural parts (aged spurs, cordons or trunks) to manage grape production. 

Pruning is an important first step to encourage good canopy growth and structure and to keep vines compact. It increases the amount of sunlight that can penetrate the fruiting zone, encouraging strong bud development and improving fruit quality.

Dormant pruning also improves airflow throughout the grapevine canopy, reducing disease risk. Good pruning practices are a critical part of grapevine disease IPM. Pruning can remove old, diseased, injured or damaged wood. Trunks, cordons and spurs can be re-established during pruning, ensuring that the vine can continually produce fruit. 

Timing

The best time to prune dormant grapevines is after the coldest part of winter but before the buds open. In Minnesota, this is generally in mid-March or early April, depending on your location in the state. Before pruning, check the weather forecast. Avoid pruning right before a cold snap to prevent additional plant stress. Be mindful of wet days when temperatures are above 50 degrees Fahrenheit, as trunk disease spores may be more active in warm, wet weather. 

If you cannot prune in late winter, you can prune after buds open. However, the disease risk will be higher and buds are more vulnerable to being knocked off the vine.

Tools

When pruning grapes, you will need three tools: hand (pruning) shears, loppers and a pruning saw. Loppers and pruning saws are especially helpful when pruning older grapevines. 

Generally, hand shears are useful for managing canes and younger growth.  Loppers have longer handles and bigger blades which give more leverage to clip thicker, more woody growth, like aged spurs and cordons. Both types of tool use a pair of “blades” to make the cut and can be described as a bypass or anvil cut. Bypass blades make a cleaner cut, as the top blade passes by the bottom blade slightly when cuts are made. With anvil blades, the top blade hits the bottom blade to complete the cut, potentially crushing the end of the pruned branch. 

Occasionally, you may need a pruning saw to remove very old, thick wood. Pruning saws have a slight crescent shape, which helps make a clean cut and promotes plant health.

Getting Started

Pruning a grapevine for the first time may feel intimidating, particularly when you think about how much plant tissue you may remove. For plant-lovers, this can seem jarring; however, the goal is to focus the plant’s energy toward producing healthy, abundant grapes. Before you begin, consider the following guidance:

• Pruning cuts on canes should be made about ½ inch above a bud. 

• Cut upright canes at an angle to encourage water to slide off the wound. 

• Use straight cuts on non-upright canes, as straight cuts leave a smaller wound.

• The goal for a healthy, established grapevine is to leave only six to eight buds per linear foot of cordon.

Pruning a New Grapevine 

• Year 1: In the first winter after planting, identify one or more healthy canes that you will allow to age into at least one trunk. A healthy cane will be tan to brown in color, with nodes about 3 inches apart. Remove other canes at this time. 

• Year 2: During the second growing season, the vine will grow and produce additional canes. The following winter, you will select healthy canes to train into the cordons of the vine. While the vine will eventually have only two cordons (one on each side), you can keep more than two canes and decide which ones to keep for cordons after the growing season.

• Year 3: During the third growing season, the new cordons will send out shoots from every node to become new canes by the end of the season. Over the winter, prune each of these new canes to have two to four buds. 

• Year 4: The following season, the new canes will mature into the first set of spurs and produce shoots. These shoots will produce fruit and turn into woody canes by the end of the growing season. At this point, the vine will be pruned as an established grapevine. 

Pruning an Established Grapevine

After a grapevine is fully established, you will continue pruning to maintain fruit production and to ensure plant health. Ongoing pruning can seem aggressive: nearly 90% of canes from the previous growing season should be completely removed or cut back to a spur with between two and four buds. These buds will bear fruit-producing shoots the following growing season. This cycle repeats itself annually, until winter injury, disease or age leads a gardener to replace a spur, cordon or trunk. 

Before making any pruning cuts on established vines, carefully assess the whole vine to identify areas of weak fruit production. Look for unproductive wood, such as areas impacted by winter injury, disease and weak, unhealthy canes. Additionally, identify “blind wood,” a term for areas of the vine with few nodes.

Weak canes, those thinner than a standard pencil, should be removed, as they have little energy to contribute towards shoot growth the following season. If a section of your vine only has weak canes, prune the canes to one node, to force their energy toward growth. 

When pruning, you may encounter “bull” canes, or fast-growing canes with a girth larger than a permanent marker and distantly spaced nodes. If possible, bull canes should not be allowed to develop into spurs, trunks or cordons, as they are less productive and more susceptible to winter injury. 

Finally, remove any lateral canes. Lateral canes branch from the main cane during the growing season and divert energy, like a sucker on a tomato plant. These canes are the same age as the main cane and will have smooth, tan bark. Completely remove lateral canes by cutting them back to the main cane. Then, prune the main cane to two to four nodes. 

Keep healthy, “goldilocks” canes to prune into new spurs. These canes are just right: the girth of a permanent marker, tan to brown in color and have nodes that are about three inches (the width of one fist) apart. Prune these canes to two to four nodes. Ideally, the healthy canes you keep and prune will be closer to the bottom of the spur and the closest to the cordon. This prevents spur growth from becoming excessively tall and reducing canopy space and productivity. If the only healthy canes are high up on the spur, cut back the lower, weaker cane to a single node, while leaving two to three nodes on the top cane. You can then remove the top cane the following year.  

In addition to pruning the canes, you may need to replace old, unproductive or damaged spurs. During the growing season, if you see a new shoot growing next to an old spur, leave it alone. When pruning the following winter, keep the new cane and cut it back to two to four buds to become a new spur. Remove the old spur.

Remember that, when pruning effectively, you will remove approximately 90% of the previous year’s growth (Figure 1). To maximize fruit production, remove some canes completely; do not simply cut back every cane to a few nodes. The final goal for a healthy, established grapevine is to leave only six to eight buds per linear foot of cordon. Vigorous pruning can feel intimidating. However, fruit production is the ultimate goal and grapevines thrive with heavy pruning! 

Figure 1: A drawing of a dormant grapevine before, during and after pruning. Note the parts of the vine highlighted in red were removed in pruning. The majority of each cane was removed to encourage fruit production.

Test Your Knowledge

Additional Resources

• Growing grapes in the home garden from University of Minnesota Extension

• Webinar: Pruning cold climate wine grapes from University of Minnesota Extension

• A stepwise guide to dormant pruning and training young grapevines from Penn State Extension