When a grapevine appears dead along its trunk but suddenly begins producing healthy green leaves and shoots near the ground, don't assume the vine needs to be replaced. The root system may still be healthy and capable of producing enough vigorous growth to rebuild the vine.
One useful tool for this situation is a grapevine grow tube.
What Does a Grapevine Grow Tube Do?
A grow tube is a protective plastic or translucent sleeve placed around a young grapevine or developing shoot. Grow tubes are commonly used when establishing new vineyards, but they can also be useful when rehabilitating an established vine that has suffered trunk damage or dieback.
Grow tubes can:
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Protect tender new shoots from wind and accidental damage.
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Reduce damage from rabbits and other small animals.
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Create a warmer, somewhat more humid environment around young growth.
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Encourage shoots to grow vertically toward the opening at the top of the tube.
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Make it easier to develop a strong, relatively straight replacement trunk.
The tube itself doesn't force the grapevine to grow upward. Instead, the combination of the enclosed environment, access to light at the top, and proper staking helps encourage vertical growth.
What If the Top of the Grapevine Is Dead?
If the upper trunk and cordons appear dead but new growth is emerging from the bottom of the vine, the first step is determining whether the old wood is actually dead.
Try a simple scratch test. Gently scratch a small section of bark with a clean tool. Green tissue underneath indicates living wood. Brown, dry tissue generally indicates that portion has died — and may point to trunk diseases such as Eutypa dieback, a common cause of grapevine decline.
Work downward until you locate living tissue. Dead sections can then be pruned away with clean pruning tools.
If the trunk is completely dead but vigorous shoots are emerging from the base, one of those shoots may potentially become the vine's new trunk.
Select One Strong Shoot
Choose the strongest, healthiest and straightest new shoot emerging from the appropriate portion of the vine.
Place a sturdy stake next to it and carefully position a grow tube around the new growth. As the shoot grows through the tube, continue training it vertically along the stake.
Once the shoot emerges from the top, loosely secure it to the stake rather than allowing it to bend or trail along the ground.
You may initially keep a second healthy shoot as insurance. Once the primary shoot is growing vigorously and appears well established, competing basal shoots can generally be removed so the vine can concentrate its energy on rebuilding the replacement trunk.
A Critical Consideration for Grafted Grapevines
Before selecting a basal shoot, determine whether your grapevine is own-rooted or grafted.
With an own-rooted vine, healthy new growth from the base is genetically the same variety as the original vine.
A grafted grapevine is different.
If the new shoot originates above the graft union, it may be used to rebuild the desired grape variety. However, shoots originating below the graft union are generally coming from the rootstock.
Training a rootstock shoot into the new trunk could leave you with a healthy grapevine—but not necessarily the grape variety you originally planted.
Don't Leave the Grow Tube on Forever
Grow tubes are primarily an establishment and training tool.
In warm climates, temperatures inside a grow tube can become considerably higher than the surrounding air. Periodically inspect the vine for excessive heat, moisture, disease, insects or restricted growth.
Ventilated grow tubes can be particularly useful in warmer backyard vineyards.
Once the replacement shoot is strong enough to remain securely attached to its stake and continue toward the trellis, the grow tube can be removed.
Don't Give Up on a Grapevine Too Quickly
A dead-looking trunk doesn't necessarily mean a dead grapevine.
An established root system can contain significant reserves, allowing a damaged vine to produce vigorous new basal growth. When that happens, careful pruning, shoot selection, staking and a properly used grow tube may allow you to rebuild the grapevine rather than replace it.
For the backyard grower, that can mean preserving years of established root development while essentially giving the above-ground portion of the vine a fresh start.
When your grapes are eventually ready to harvest, you'll also want the right winemaking equipment on hand. Our guides on choosing between carboys and stainless steel fermenters and creating proper airlocks for home winemaking are good starting points for planning your setup.
Thinking About Taking Your Winemaking Hobby Further?
Growing healthy grapes is only one part of turning a backyard vineyard and winemaking hobby into something more.
CellarCraft Marketplace's How to Legally Convert Your Hobby Winemaking Into a Profitable Business provides practical guidance for hobby winemakers interested in understanding the licensing, compliance and business considerations involved in legally selling wine.
Visit the CellarCraft Learning Center to explore winery business guides, vineyard resources, winemaking education and DIY equipment plans designed for small-scale and aspiring winemakers.