A few weeks ago my wife, Linda, made a special request. “Would you buy me a chain saw,” she asked.
When I asked why, Linda said she had to cut down the grapevines in the woods.
“They’re everywhere. They climb all the trees and kill them. I just want to cut the main stems at ground level,” she explained.
Grapevines
Linda clearly misunderstood the situation so I tried to explain. Grapevines do not kill trees. They are not parasites. They need trees to support themselves as they climb skyward to sunlight.
Furthermore, grapes are an important food for wildlife during the summer months. In fact, next to acorns and other nuts, it can be argued that grapes are the most important wildlife food in deciduous woods.
Food source
Bears, raccoons, opossums, skunks, and foxes are among the mammals that relish grapes. Game birds such as turkeys, ruffed grouse, bobwhite, and ring-necked pheasants frequent grape tangles when the fruits are ripe. And virtually all fruit-eating songbirds love grapes. That list includes catbirds, brown thrashers, robins, a variety of vireos and warblers, and even pileated woodpeckers.
Grapevine tangles also offer dense nesting and escape cover throughout the year. Catbirds and thrashers often nest in thickets overgrown by grapevines, and at least 16 species of songbirds use grapevine bark as nesting material.
In fact, I’ve never found a cardinal nest that was not made primarily of grape bark.
I rested my case, and Linda agreed to put off the purchase of a chain saw. “For now,” she said.
Climbing vines
Grapevines grow as woody climbing vines. Leaves are simple, large, heart-shaped at the based and often lobed.
Fleshy tendrils originate from the stems and grab onto tree branches to help the vine climb. As grapes ripen later in summer, they become dark blue or black.
Two other woody vines, one benign and one nasty, can be confused with grapes. Virginia creeper climbs like a grapevine and produces small, dark, grape-like fruits that are also important foods for wildlife. Its compound leaves typically consist of five small leaflets.
Poison ivy, a botanical chameleon, can grow as a vine, a shrub, or even a small tree. Its leaflets come in threes (hence the adage, “Leaflets three, let it be.”).
Finally, the surface of the leaves is always shiny, evidence of the oil (ursuhiol) that causes the rash. This irritating oil is present in all plant parts all year long, and it can remain active on dead plant parts for up to five years.
Poison ivy
Anytime you suspect you may have encountered poison ivy, wash the exposed skin with soap and water within two hours of exposure to prevent the urushiol from bonding to the skin.
With images of woody vines fresh on our minds, Linda and I spent Mother’s Day weekend along the Allegheny River in Foxburg, Pa. We were there for the annual Nature Fest, and on Saturday morning we scattered on field trips. One man in my group was Bill Paxton, a forester from Latrobe, Pa.
As we wandered the woods along the Allegheny River identifying birds, wildflowers, and trees it felt like a master class in natural history.
Sunlight
At one point Paxton pointed to a tall tree and said, “See how the tree provides access to the canopy for the grapevines? They need the sunlight.”
I then told Bill of my wife’s opinion of grapevines and asked if he could later give Linda a forester’s perspective.
When the morning field trips ended, I introduced Linda to Paxton. She spent the next 10 minutes learning about grapevines from an expert. He pleaded with her to appreciate grapevines.
“They’re just too valuable,” Paxton said.
Commercial value
He also added that grapevines can increase the commercial value of tall trees.
“When grapevines climb tall trees they sometimes prune side branches and leave behind longer, straighter, more valuable logs,” he explained.
But Bill also added that if grapes invaded the yard and aggressively climbed some favorite trees, it would be OK to remove them for aesthetic reasons.
Outweighing ecological value
That final concession did the trick. Linda agreed that the ecological value of grapes outweighed their aggressive nature.
“Cancel the chain saw order,” she said.
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4/23/2020 better late than never.
ridiculous. of course wild grape vines can kill trees. they have done so all throughout our wooded farm acreage. the mechanism is that their leaves shade out the host tree’s canopy. Let me quote your article:
“When grapevines climb tall trees they sometimes prune side branches and leave behind longer, straighter, more valuable logs,” he explained.
How do you suppose they do that? simple, they shade them out. I don’t disagree with the value of grapes for wildlife, but if you value your trees, especially saplings and younger trees that are in direct sunlight (especially along edges of woodlots, as grape vines are shade intolerant and thrive in sunlight) then snip them at their base in the spring before their leaves engulf the trees. I recommend doing the same for large trees that you don’t want damaged as well. cheers, -john w. (no degree needed)
I beg to differ about the vines, they are slowly killing all the vegetation in both my side lots. Their invasive root system is taking over the floor of the lots and not allowing anything else to grow. They are killing shrubs slowly and if I don’t kill the vines there will be no shrubbery. They’ve killed four trees so far because they have run rampant for the past several years. I only caught it during this pandemic because it’s a summer home and I’ve been able to spend good time up here. Maybe you all have trees to spare but I do not. The lots provide me privacy and I am distraught on having let them take over so much.
Bring on the chain saw! These vines do kill trees.
Just check USFS. Vines take nutrients away from tree roots, shade the upper canopy of tree leaves from proliferating, the weight of the vines is tremendous especially when weighted down with snow or ice. The article is clearly incorrect.
I discovered a seldom used patch of woods last year in fairly inaccesible piece of land next to my neighborhood and noticed large vines climbing up into the canopy. The vines were eerily beautiful. They were no doubt damaging and killing some of the younger trees and no doubt stressing some of the large mature oaks. I started to cut them before fully researching and now recognize that many were likely old native grapes. I wish I had waited to act as I assumed they were invasive. The woods almost had a haunted quality when I discovered them and I am questioning the hubris and haste with which I acted.
I would love to see these massive shaggy wooded grapevines climbing the trees as lovely, but I can see how they are strangling the life out of trees mostly by keeping them from getting enough sunlight. We are cutting them here in West Michigan because they are obviously taking over and killing even some mature trees.
Where we are the grape vines can even become massive. I’ve seen them take out entire valleys of trees over a relatively short time. In addition, when they get out of control, and grow way to large, they don’t actually bear grapes, or barely so in most cases. And the ones that have settled on smaller trees (10 to 15 feet in height) do bear grapes. Allow me to give you some food for thought. On a 200 acre spread of land, in the past 2 years, I’ve found about 3 places where the vines were bearing grapes. All the rest of the acreage were not. ALL grape vines will most assuredly kill the trees they’re attached to. In all my more than 60+ years of viewing these vines, I’ve witnessed only a half dozen or so where the tree came out the victor, and the vine died. A tree, ANY tree will eventually die from these grape vines being attached. In addition, when the vine attaches to young, small, sapling trees, those trees most assuredly die. In an effort to survive, the vines will use these small dead and dying trees as a step ladder in order to attach to the branches of nearby larger trees, and then climb up and kill those trees, too. One last thing. In our area, the few grape bearing vines I’ve witnessed through the years have remained entirely untouched by birds and animals. I’ll grant you, there are many things to eat here, so that could be maybe why, but then again maybe not. I’m surmising that these bitter, under-developed northern grapes are not well suited for bird, bug, bear, and deer food. In the winter months when deer are scavenging for food, the dried grapes on the vines are still not touched by even the starving deer. Oh still another thought. When a tree is a full-grown size and you cut a large grape vine from it. The vine will send up new spouts, but it’ll never catch up with the big tree again. So for gosh sakes, CUT THOSE THINGS. They’ll still live, and so will your beautiful, majestic trees.