Briars and Ivy taking over Ireland

yosemitesam1

https://www.boards.ie/discussion/comment/122030026#Comment_122030026

Darkness caused by a vigorous tree.

Base price

@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.

magicbastarder

https://www.boards.ie/discussion/comment/122028428#Comment_122028428

given that if you google 'does ivy harm trees' and you get multiple differing answers in the responses, it'd be good to include the source of the text in what you pasted there; we don't know if it came from a tree surgeon, a company selling herbicide, etc…

from the RHS:

"On most trees that are in sound health and are not being grown for their attractive bark, ivy can be allowed to grow on the trunk without concern for the tree's health or vigour"

https://www.rhs.org.uk/weeds/ivy-on-trees-ground-cover-weed

twin_beacon

https://www.boards.ie/discussion/comment/122028402#Comment_122028402

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?

Shoog

https://www.boards.ie/discussion/comment/122030035#Comment_122030035

Trees are complex and they exude chemicals which resist infestations of all types.

magicbastarder

https://www.boards.ie/discussion/comment/122030581#Comment_122030581

Darkness

Caused by a vigorous tree

All that I see

Absolute horror

(Apols to anyone for whom that makes no sense. I have it as an earworm now)

standardg60

https://www.boards.ie/discussion/comment/122031072#Comment_122031072

It is a parasite in my view, once in the canopy it competes with the leaves, outgrows and smothers them, it wraps around branches preventing them from expanding exactly like tying a rope around them would, and a heavy infestation around the trunk traps moisture against it no differently to piling soil or mulch around it.

In a forest Ivy isn't as destructive as it's kept at bay by the full canopy. This isn't the case in hedgerows which are a much more modern concept so you can't compare the two and say well it can't be doing any harm now.

Ivy is as bad a monoculture as any other suppressing species at the moment, I think everyone can see it's become massively prevalent the last few years, perhaps again due to the wetter climate. It should be controlled.

A national Ivy severing day is a great idea in my book.

yosemitesam1

https://www.boards.ie/discussion/comment/122031310#Comment_122031310

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.

standardg60

https://www.boards.ie/discussion/comment/122031379#Comment_122031379

Very true, there has been a distinct lack of management of hedgerows the last few years, it's a dying art. How many even look at them now?

Shoog

https://www.boards.ie/discussion/comment/122031310#Comment_122031310

If you stick your hand into a dense ivy growth it's bone dry even on the wettest day. No water is held against the trunk because no water gets there.

Shoog

https://www.boards.ie/discussion/comment/122031468#Comment_122031468

Hedgerows are typically flailed to death. The worst form of management.

Birdnuts

https://www.boards.ie/discussion/comment/122029682#Comment_122029682

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

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We have mature trees with Ivy growing on them and others that don't - both adjacent to one another along the same old semi disused farm roadway. When we were in the GLAS scheme I put the bat boxes on the trees that didn't have Ivy growing on them. I will take a photo tomorrow (weather permitting) and post it here.

As others have mentioned Ash die back is killing hedgerow trees. I've posted previously that Dutch Elm disease has forever changed our hedgerows and unfortunately Ash die back and now more recently Fireblight is going to decimate them even more. A in law relative in NCD received a Crann award in the 80's for planting Elm saplings throughout the road & farm hedgerows. Within fifteen years they were all dead including the rest of the mature trees.

monseiur

https://www.boards.ie/discussion/comment/122029682#Comment_122029682

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.

whisky_galore

https://www.boards.ie/discussion/comment/122031517#Comment_122031517

Flailed or demolished to turn farms into ranches.

GreeBo

https://www.boards.ie/discussion/comment/122031127#Comment_122031127

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

Shoog

https://www.boards.ie/discussion/comment/122033282#Comment_122033282

Why wouldn't it ?

GreeBo

https://www.boards.ie/discussion/comment/122031072#Comment_122031072

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.

GreeBo

https://www.boards.ie/discussion/comment/122033285#Comment_122033285

Well "resist" would seem to imply that there would be a downside to no-resisting, otherwise why would the tree waste energy "resisting" when it could put that energy into growing or flowering?

Lime Tree Farm

https://www.boards.ie/discussion/comment/122033311#Comment_122033311

Allelochemicals

magicbastarder

i don't think too many of our native trees are allelopathic.

twin_beacon

https://www.boards.ie/discussion/comment/122033304#Comment_122033304

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.

twin_beacon

https://www.boards.ie/discussion/comment/122031310#Comment_122031310

Your first paragraph is very wrong. It does not prevent branches from expanding, I think you are underestimating the power of a growing tree. Have you never seen a concrete wall cracked due to growing tree roots? Ivy wrapped around tree branches is nothing to it. Regarding moisture, its actually the complete opposite. The evergreen leaves of the ivy deflect rain away from it.

The forest you are referring to would be a softwood plantation, which are basically barren on the ground. The trees are planted close to each other to trick them in to growing straight. As a result, very little light reaches the ground, and very little grows. A native hardwood forest is very different.
Hedgerows are no different, Ivy will only attach itself to branches that are strong enough to support its weight. It can't attach itself to the small branches that hold the leaves. A flail hedge cutter is also a modern concept, after a hedge row has been cut back, it may look like its being choked with Ivy, but that's because the small branches that hold the leaves have been removed. Those small branches will regrow in time.

As I said in my previous post, people can probably see Ivy becoming more, "prevalent" is due to ash dieback. People may assume the tree was killed due to the Ivy.

standardg60

https://www.boards.ie/discussion/comment/122034006#Comment_122034006

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.

twin_beacon

https://www.boards.ie/discussion/comment/122034272#Comment_122034272

We have trees just like that in our land for as long as I can remember, I'm looking at two of them right now. The Ivy is causing them no issues.

GreeBo

https://www.boards.ie/discussion/comment/122033892#Comment_122033892

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.

GreeBo

https://www.boards.ie/discussion/comment/122034006#Comment_122034006

I've seen ivy take down walls, I think you are underestimating the power of growing ivy!

Shoog

https://www.boards.ie/discussion/comment/122034658#Comment_122034658

Ivy will eventually take down already dead or dying trees, and it will certainly take down an ancient crumbling wall. They were coming down anyway.

Where is the surprise in this ?

magicbastarder

https://www.boards.ie/discussion/comment/122034402#Comment_122034402

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.

not sure if i understand - surely when the tree is in leaf, the left hand side of the tree is shading the right hand side of the tree?

anyway, according to the RHS ivy does not damage trees. googling it throws up a lot of american results - but ivy is considered an invasive pest in america, and most of the academic results (rather than garden maintenance results) i see there mainly relate to an increased risk of windthrow, not that the ivy actually kills the tree.

Glenomra

Its not just ivy and briars. The area that I am most familiar with, East Clare, particularly the low lying areas, is succumbing to rushes. As fewer young people farm and with increasingly wet weather, more and more land is 'reverting' to nature.