Briars and Ivy taking over Ireland

I don't understand why people don't just spend a couple of hours with the chainsaw and cut the ivy around the bottom of trees.

I was at it yesterday evening myself and will take great satisfaction over the coming weeks seeing it die away.

Same with briars I'll be hitting them with Grazon 90 when I get time.

How would you like it if someone whipped off your Winter coat. Ivy protects trees and wildlife.

If its not a parasite and not causing any damage, what exactly is the tree "resisting"?

Also, how do they "resist" the Ivy?

That's another thing Ivy does, it traps moisture against the trunk which eventually rots the bark.

I've cleared ivy from trees that were half dead from it and they've subsequently recovered. It's an old wives tale that a tree falls or dies because it was weak itself and nothing to do with the Ivy, it's all to do with it.

@Biscuitus - when you started this thread four years ago I never thought that there would be such a divided opinion about Ivy. The Briar's are getting a easy ride on this thread and I consider them more a problem pulling down fences, spreading suckers etc. IMO Blackthorn and Whins/Gorse are and equally bigger problem when they get out of control.

Ivy is not a parasite. By defination, a parasite takes nutriants from its host. Ivy attaches itself to trees, but it doesn't penetrate the bark. Its has own root structure, and its own leaves. If it was a parasite, it couldn't survive if it was attached to a wall or a house.

Ivy doesn't weaken tress, and it doesn't obscure light, infact its the trees that block light to the Ivy, as when the leaves appear on the trees, it blocks the sunlight to the trunk of the tree, which is where the Ivy is attached to. For this reason, Ash trees are the most comon tree to see with Ivy as they are the last trees to get their leaves in the spring. Ash dieback disease is probably having an impact here too, with more and more Ash trees having "dead" branches. There are around 10 large Ash trees beside the house here (without ash die back for now), 4 of the trees are covered in Ivy, when the leaves comes on them, you can see its having zero impact on them.

Ivy is a native species, its been here as long as there have been Ash and Oak trees in Ireland. If Ivy killed trees, then wouldn't it have killed off the large forests in Ireland that existed here after the last Ice Age?

What you're seeing really is declining vigour in hedgerows. For most of the past 1000 years they were highly managed areas, coppicing, pollarding and layed regularly with gaps filled in regularly. Trees that lost their vigour were replaced.

There has been very little management of hedgerows to maintain vigour in more recent times. A run of a hedge cutter won't do it for the long term.

FFS - if want to do something usefull for native trees/woodland you would be far better employed devoting such energies to removing the likes of Rhodendron, Laurel, Snowberry etc. that are currently decimating what little native woodland we have.

https://www.independent.ie/opinion/comment/sarah-carey-its-war-down-there-neutrality-not-an-option-for-rangers-on-path-of-killer-rhododendron/a914251062.html

Well done Sami23, be sure to paint the stumps with Roundup or similar immediately after cutting otherwise it will grow back with even more vigour. I have learned that lesson the hard way. Cut every stalk twice a few inches apart the gap will make it easier to paint the stump.

Mix say half a litre of Roundup with one or two litres of white water based paint,(instead or water) Any old light coloured paint will do, it's to mark the stumps as you go along. Be sure to wear PPE when handling & applying.

It's very important to apply Roundup within a few hours of cutting as the cut stump produces a clear lacquer type resin - when it hardens the weedkiller will not penetrate it so will be ineffective.

Why would the tree be doing this if Ivy causes no harm?

Ivy is taking the water and nutrients from the same ground that the tree is. I dont think anyone mentioned anything penetrating anything else?

Ivy 100% obscures light from trees, there are several examples of this in the thread already. Deciduous trees dont have leaves in Autumn and Winter, yet the Ivy is still growing and indeed flowering and fruiting over Autumn and Winter.

Ivy doesn't just grow on the trunk of trees, it grows towards the sun, again, look at the multiple examples in this thread. Of course it starts at the trunk, since this is the part of the tree on the ground….

This idea that just because something is "native" means it can do no harm is just misguided. Without something to keep it in check, anything will take over. If humans dont control ivy in Ireland, what will in your opinion?

I'm pretty sure that there were no fields, walls, fences and hedgerows to keep animals away from the Ivy post the last Ice Age, but perhaps I am doing the Neanderthals a disservice and they were indeed working away in their farms on their Masseys.

Allelochemicals

A tree will require a lot more water/nutrients from the ground than Ivy, as a result, trees have much larger and deeper roots. Ivy can never out compete a tree for water/nutrients.

They do NOT obscure light from trees, as the Ivy doesn't grow on the small branches where the leaves grow, as they physically can't support its weight. They can cover the tree trunk and the larger branches, but that has zero impact on the tree regarding light, as long as the trees leaves get sunlight that's all that matters. Even trees that are covered in Ivy (see pic below), the small branches that hold the leaves reach well past the Ivy.

"This idea that just because something is "native" means it can do no harm is just misguided"
It depends on what you mean by harm? Our native trees have existed side by side with Ivy since the last Ice age. If Ivy killed trees, wouldn't the vast forests that covered Ireland have been killed long before people arrived?

"Without something to keep it in check, anything will take over. If humans dont control ivy in Ireland, what will in your opinion?"
Why do we need to keep a native plant species in check? Its not an invasive plant species (and we have plenty of those to worry about), its living in harmony with the other native plant species we have here.

The problem with Ivy is that people think its "unsightly", and they believe all the stories about it killing trees to justify their want to remove it. Its really compounded over the last few years where ash dieback disease has really taken over, to the point where its hard to drive 5 mins and not see an ash suffering from it. Many of these trees will have Ivy on them, and many people will just blame the Ivy.
IMO, there is nothing more ugly than dead ivy on a tree where someone cut it.

Look up arboreal Ivy. It is this form that crowds canopies, it doesn't need any support.

The moisture that gets trapped against the trunk is between the bark and the Ivy stems, nothing to do with the leaves deflecting moisture.

The tree in your pic is under severe pressure from the Ivy infestation IMO, only a matter of time before it falls or gets completely crowded.

I never said it would "out compete" I said its taking water and nutrients that otherwise could be used by the tree.

OK, so explain how, in your picture, the Ivy in the middle of the tree somehow isnt shading the entire right hand side of the tree when the sun is coming in the from the left? I think you are assuming, incorrectly, that the sun in Ireland is directly overhead.

I already explained this, our native trees existed for years with wild animals keeping the ivy in check. They cant do this anymore due to things like walls and fences and motorways.

We have to keep it in check because we have prevented it from being kept in check naturally. Its not living in harmony, thats why we see trees and walls and forest floors covered in ivy.

I think you need to move on from Ash die back. No one is talking about that. People are talking about trees and hedges and fences and walls being covered in ivy and briars. Forget about dead trees with ivy, the problem is everything else covered in the stuff.

Dead ivy looks terrible on trees, so don't let it grow on them in the first place. A nice copse of trees that would otherwise have no issues in winter risk being pushed over by the winter wind if they are all covered in ivy.

When the tree isn't in leaf, the ivy still is.

Your second paragraph raises an interesting question, what makes it a pest in the US but not here? What is it that exists in Ireland to control it that doesn't exist in the US? Note that I am not arguing about it being native, more what problem does it cause in the US that it doesnt over here.

Grass doesn't grow much in winter because of cold temperatures and lower sunlight strenght limiting photosynthesis, ivy faces the exact same problems. It will only hold its leaves in order to maximise growth at the shoulders of the year. It's not going to be growing vigorously through the winter

So how have our other plants adapted so as not the suffer the same issue?

Surely Ivy only causes an issue to unhealthy US trees and so why do they care?

Windthrow is a very significant issue to the tree!