climbers and trees , how much is too much

Greetings!

I have been reading different views on the topic of climbers and trees. It seems that in general permaculture view of the layeres, we have the vines/climbers using trees, seems also natural. But Ive also heard some permaculturists say that in practice this doesnt really work and can kill or seriously weaken a tree. In my land I have several cases of grape vine deeply mixed into fig trees and orange trees just to name a few, all the way to the top of the tree in some cases. Some are quite beatiful to see actualy, seems almost just like one single tree, with figs and grapes all growing in it as its so interwined.  I have been wondering if to leave it or if to prune the vine down. Does anyone have practical experience of this over a period of years and possible effect on the trees?

thanks

Grapes produce the most fruit when heavily pruned. My grapes grow on trellises, trees. and shrubs. I prune them the same whether they are on a tree, a shrub, or a trellis. If a grape has a trellis to grow on, and a tree, then I typically cut it back to the trellis each year, and it can grow as much as it likes into the trees.

Even ignoring the vine's leaves shading the tree's leaves, one problem with tendril climbers like grapes is that the tendrils can wrap around and girdle small branches and twigs on the tree.  The tendrils will also wrap around and girdle parts of the grape vine as well, which is how an unpruned vine can end up strangling itself unless pruned annually.  In nature, when they climb a tall tree and can spread unchecked on the tree, the strangling/girdling tendency is reduced, but in most settings, grapes are cut back to a greater or lesser extent to limit their spread, which encourages vine branching and tendril girdling.  

Mike Turner wrote:Even ignoring the vine's leaves shading the tree's leaves, one problem with tendril climbers like grapes is that the tendrils can wrap around and girdle small branches and twigs on the tree.  The tendrils will also wrap around and girdle parts of the grape vine as well, which is how an unpruned vine can end up strangling itself unless pruned annually.  In nature, when they climb a tall tree and can spread unchecked on the tree, the strangling/girdling tendency is reduced, but in most settings, grapes are cut back to a greater or lesser extent to limit their spread, which encourages vine branching and tendril girdling.  

Mike, so if I  understand you correctly, if left unchecked and unpruned its actually less of an strangling effect on the tree than if pruned. But in any case, another factor of concern I had was exactly that, in one of the trees, indeed, the top layer of leafs of the grapes seems to almost cover half the top canopy, so shading a lot the tree... on the other hand, I guess the idea is that in nature it normally works like that... still a little confused on this aspect.

Didn't the "vine layer" idea come from studying tropical food forests?  Maybe vines are less of a threat to trees in the tropics.  They can definitely be a threat in New England - the porcelainberry in our yard nearly killed several trees.

Vines and trees can mix to a certain extent but you must keep the vine from circling the tree's trunk or the tree will end up dying from strangulation.

Even in the rain forests of the world vines do kill trees by girdle strangulation.
This is just the nature of growth pattern for vines, they want to climb and to do so well they have to circle the upright support (tree trunk).
Even an annual like passion fruit can kill a tree with the tendrils girdling the branches which then die, resulting in a tree with not enough leaves to produce food.
Results of that are the tree dying from starvation.

While in most cases this can take several years, it can devastate young trees in as little as one year.
Which makes the idea one that is for the most part not the best idea in the world of growing things.
Of course if the support tree happens to be one you don't really want where it is, and it is too large to move, then let the vine kill it.
The one thing in this instance you have to plan for is that now dead tree falling over from a wind storm.
Where will it most likely land? It would not be good to have a strangled tree fall on or through your roof in a thunder storm or big blizzard.

We have grape and muscadine vines  but these are on vineyard trellises except the ones in the woods.
Muscadine vines tend to grow straighter than most vines and we have a few that even stretch from one tree to another to another.
So far the muscadine vines I have found, that were already growing here when we bought the property, have not shown themselves to be a problem for the trees they live among.
We did have some non-food producing vines that were trying to kill some of the larger oaks. Those vines are now cut  down and removed, the oak trees have made a tremendous comeback from my taking their killers down to the ground.
I now chop the vines around 5 times a year and a few are already dead from not being able to produce their own food.

I would recommend never letting a vine circle a tree for any length of time.
One of our 100+ year old oaks lost a main branch because of a strangling vine (now completely gone).

Redhawk

From the vine's point of view, the vine wants to take the tree's place in the canopy.  With tree species like the strangler figs, this literally does happen with the fig growing down, encircling and strangling the host tree, killing it, then the fig becoming a tree in its place as the dead host's trunk rots away.  Similarly vines could kill their host tree, but then spread to other nearby trees before their current support rots away. But at the same time the trees are evolving to survive in the presence of the vine.  In the case of the situation in the wild where a native muscadine or fox grape climbs up a native tree in the forest, they two plants usually tolerate each other without problem because the two species have evolved in each other's presence.  You can see the grape here and there up in the canopy, but it doesn't overwhelm the tree with its leaves unless the tree is already sick or dying.   But in a non-natural situation when its a vigorous non-native vine such as kudzu, Japanese honeysuckle, Chinese wisteria, or oriental bittersweet climbing a native tree, the vine quickly covers, shades out (in the case of kudzu) or strangles (honeysuckle, wisteria or bittersweet) the tree.  In most cases when you are growing a vine into a tree in your garden, it is not a totally natural situation, so you have to monitor things to make sure the vine doesn't overwhelm the tree.

Pruning increases the vine's potential for strangling the vine or the tree since it increases the number of lateral branches produced by the vine and these lateral branches then latch onto each other and form a mat over a smaller area.  Pruning has to be done in a manner to prevent this from happening and traditional vine pruning techniques are aimed at controlling this.

Hello Mikal
Few practical experience but some hints.
Your trees should grow higher than your vines to be sustainable for both. You could use trellising trees but there best for wood producing.
Pruning is needed for both tree and vine.
Not all vines  strangulates. And if they do , keep in mind the lifespan of the tree. If you plant a arguta kiwi next too a 200 year old oak he/she will be not bothered by the vine in the coming 50 years.Then your arguta will be long lived and disappearing.
If you ever allow Ivy in too a tree then...?
Witch vines are you planning for? "annual climbers" like hops and runner beans  don't ruin a tree.
My experience with climbers are limited but i can tell you this:Runner beans under linden do grow with a low revenue. they need to prove there hardiness .
Beans are good stranglers and peas are good thatchers. Beans grow well in to trees and peas grow in to shrubs. The climbing beans!!!
I grow Vicia pisiformis and it gives 50 grams seed each plant? Its perennial and low maintenance. Ideal for chicken fodder.

I have volunteered grape vines that have overwhelmed my blackberry bushes,AND the mulberry trees!
They made very little in the way of grapes and they're quite rude, so the I will be cutting them to the ground,and only allow a limited amount of growth next year.
Maybe I will move them,let them climb the Rose of Sharon,which is holding it's own against some climbing honeysuckle.