How To Prune A Grapevine

Learning how to prune a grapevine is the single most important skill you can master for a healthy, productive vineyard. It might seem intimidating at first, but with a little knowledge, you’ll see it’s a straightforward and rewarding winter task. This guide will walk you through the why, when, and how, giving you the confidence to make the right cuts.

Pruning isn’t just about controlling size. It’s about directing the plant’s energy. Grapevines produce fruit on new shoots that grow from one-year-old canes. Without pruning, the vine becomes a tangled mess of old wood, producing lots of leaves but few, poor-quality grapes. Proper pruning ensures sunlight and air reach the canopy, preventing disease and encouraging sweet, abundant clusters.

Before you make your first cut, it’s crucial to understand the basic structure of a grapevine. This will make the pruning process logical.

Grapevine Anatomy: Key Terms

Trunk: The main, permanent upright stem.
Arms (or Cordons): Permanent horizontal branches growing from the trunk, often trained along a wire.
Canes: The one-year-old growth from the previous season. They are smooth, thin, and have buds. Fruit comes from these.
Spurs: Short sections of cane cut back to only 2-3 buds.
Buds: The small, slightly swollen bumps on canes. These will become new shoots, leaves, and fruit clusters in the coming spring.

When is the Best Time to Prune?

Timing is everything. The best period for pruning is during the vine’s dormant season, after leaf fall and before spring bud break. This is typically in late winter. Pruning too early can make the vine vulnerable to winter injury. Pruning too late causes the vine to “bleed” sap, which isn’t usually harmful but is wasteful.

Aim for a time when the worst of the freezing weather has passed but well before the buds start to swell. This is often February or March in many climates, but it depends on your local conditions.

Essential Tools for the Job

Bypass Pruners (Secateurs): For clean cuts on canes up to about 1/2 inch thick.
Loppers: For thicker canes, up to about 1.5 inches.
A Pruning Saw: For removing old, thick wood from the trunk or arms.
Gloves: To protect your hands from thorns and rough bark.

Always ensure your tools are sharp and clean. Disinfect them with a mild bleach solution between vines to prevent spreading disease, especially if you suspect any issues.

The Two Main Pruning Systems: Cane vs. Spur

Most home grapevines are pruned using one of two methods. Your choice often depends on the grape variety and your training system.

Cane Pruning

Common for varieties like Concord and many table grapes. This method involves selecting a few strong, healthy canes from the previous year’s growth and cutting them back to a specific number of buds. You will also choose renewal spurs.

Identify 2-4 healthy canes that grew last year, ideally about as thick as your pinky finger.
Cut each selected cane back, leaving 8-12 buds on each. These are your “fruiting canes.”
Select 2-4 more canes closer to the trunk and cut them back to just 2 buds. These are “renewal spurs” and will provide next year’s fruiting wood.
Remove all other canes completely.

Spur Pruning

Ideal for varieties like most wine grapes (Cabernet, Chardonnay, etc.) that are trained on a permanent cordon system. Instead of long canes, you maintain short spurs along the arms.

Along the permanent arms, identify the previous year’s growth (the canes that grew outward from the arm).
Cut each of these canes back to just 2-3 buds. This short section is now a “spur.”
Space spurs about 4-6 inches apart along the arm.
Remove any canes growing in undesirable directions or that are too weak.

A Step-by-Step Pruning Walkthrough

Let’s put it all together. Follow these steps for a dormant season prune.

Remove the Obvious: Start by cutting out all dead, diseased, or broken wood. Cut it back to healthy tissue or completely to its origin.
Clear Last Year’s Growth: If you are spur pruning, cut off all the one-year-old canes that grew from the arms, except for the ones you will leave as spurs. For cane pruning, you will be selecting from these.
Select Your Keepers: Choose the healthiest, best-placed canes or spurs. They should be well-attached, have good spacing, and be about pencil-thickness.
Make Clean Cuts: When cutting a cane, make your cut about 1-2 inches above the bud you want to keep. Angle the cut away from the bud so water runs off. Avoid leaving long stubs, as they die back and can invite disease.
Thin Out the Rest: Remove all other one-year-old growth that you did not select. Your goal is to leave a manageable, well-spaced structure.
Step Back and Assess: Take a moment to look at the vine. It should look open and airy, not crowded. Ensure sunlight can penetrate the remaining structure.

Common Pruning Mistakes to Avoid

Under-pruning (Too Timid): This is the most common error. Grapevines are vigorous and can handle, even require, severe pruning. Leaving too much wood leads to a jungle and small fruit.
Over-pruning (Too Aggressive): While rare, removing more than 90% of the previous year’s growth on a very young or weak vine can stress it. Focus on the “quality over quantity” rule for canes.
Making Ragged Cuts: Dull tools crush stems, creating wounds that heal slowly. Always use sharp bypass pruners.
Ignoring the Renewal Spurs: Forgetting to leave those short 2-bud spurs near the trunk in a cane-pruned system means you’ll have no good wood for next year’s fruit.
Pruning at the Wrong Time: As mentioned, stick to late dormancy for the health of the plant.

Caring for Your Vine After Pruning

Once pruning is complete, your work isn’t quite done. Gently tie your selected canes or cordons to your support wires using soft plant ties. This trains them into position before spring growth starts, which can be vigorous.

Clean up all the pruned canes and leaves from around the base of the vine. This debris can harbor pests and diseases over winter. You can compost it if your vines are healthy, but discard it if you noticed any fungal issues.

Finally, a late winter application of a balanced, organic fertilizer or compost around the drip line can give your vine a good start for the coming season. Water it in well if the ground isn’t frozen.

FAQ: Your Grape Pruning Questions Answered

What if I make a mistake while pruning?

Don’t panic. Grapevines are remarkably resilient. If you accidentally remove a fruiting cane you meant to keep, look for another suitable one. The vine will often produce new shoots from old wood that you can train for future years. The key is to learn from the mistake.

Can I prune my grapevine in the summer?

Yes, but for different reasons. Summer pruning involves “green” tasks like thinning leaves around fruit clusters for better sun exposure or tipping back overly long shoots. The major structural pruning should always be done in dormancy.

How much of the vine should I remove each year?

As a general rule, you will remove about 70-90% of the previous season’s growth. It seems drastic, but it’s necessary. A well-pruned mature vine may only have 40-60 buds left on it to produce the coming year’s crop.

My vine is old and overgrown. How can I fix it?

Rehabilitating a neglected vine takes 2-3 seasons. In the first year, focus on removing all dead wood and selecting the best 2-3 new canes growing from near the trunk. Cut everything else away. In subsequent years, you can re-establish a proper trunk and arms using these new canes. Be patient, as heavy renovation may reduce yield for a year or two.

Pruning is an art that improves with practice. Each year, you’ll get better at reading your vine’s growth and making the right decisions. Remember, the goal is to create a balance between vegetative growth and fruit production. With these steps, you’re well on your way to a healthier vine and a more bountiful harvest of delicious grapes. The effort you put in during the quiet winter months truly defines the success of your growing season.