I'd like to kill off the ivy on a very large, old ash tree, in the hope
of preventing it becoming overly festooned with the damned stuff [like
so many mature trees, around here].

So, I've cut the ivy climbers up the trunk (and left a large gap between
two cuts on each climber), and will keep an eye out to prevent new ones
growing.

My question: is there any truth in the old saw that ivy, once securely
established on a tree, will become genuinely parasitic, and will draw
sustenance from the tree itself?

Cheers
John

In article ],
Another John wrote:

My question: is there any truth in the old saw that ivy, once securely
established on a tree, will become genuinely parasitic, and will draw
sustenance from the tree itself?

No.


Regards,
Nick Maclaren.

On 05/05/2014 19:26, Another John wrote:
I'd like to kill off the ivy on a very large, old ash tree, in the hope
of preventing it becoming overly festooned with the damned stuff [like
so many mature trees, around here].

So, I've cut the ivy climbers up the trunk (and left a large gap between
two cuts on each climber), and will keep an eye out to prevent new ones
growing.

My question: is there any truth in the old saw that ivy, once securely
established on a tree, will become genuinely parasitic, and will draw
sustenance from the tree itself?

Cheers
John




None at all. The greatest danger is that the ivy will increase windage
on the tree and may cause its downfall during gales, esp. following wet
weather.

--
Spider.
On high ground in SE London
gardening on heavy clay

On 05/05/2014 20:25, Spider wrote:
On 05/05/2014 19:26, Another John wrote:
I'd like to kill off the ivy on a very large, old ash tree, in the hope
of preventing it becoming overly festooned with the damned stuff [like
so many mature trees, around here].

So, I've cut the ivy climbers up the trunk (and left a large gap between
two cuts on each climber), and will keep an eye out to prevent new ones
growing.

My question: is there any truth in the old saw that ivy, once securely
established on a tree, will become genuinely parasitic, and will draw
sustenance from the tree itself?

Cheers
John




None at all. The greatest danger is that the ivy will increase windage
on the tree and may cause its downfall during gales, esp. following wet
weather.

On the other hand tie ivy was providing shelter and food for a number of
birds and insects
•Holly blue caterpillar feeds on the flowers buds.
•Wasps, hornets, hoverflies, bumblebees, red admirals, small
tortoiseshells and peacock butterflies, and other late-flying insects,
drink the nectar.
•Many birds, such as blackbirds and thrushes, eat the berries.

In article ,
David Hill wrote:

My question: is there any truth in the old saw that ivy, once securely
established on a tree, will become genuinely parasitic, and will draw
sustenance from the tree itself?

None at all. The greatest danger is that the ivy will increase windage
on the tree and may cause its downfall during gales, esp. following wet
weather.

On the other hand tie ivy was providing shelter and food for a number of
birds and insects
€Holly blue caterpillar feeds on the flowers buds.
€Wasps, hornets, hoverflies, bumblebees, red admirals, small
tortoiseshells and peacock butterflies, and other late-flying insects,
drink the nectar.
€Many birds, such as blackbirds and thrushes, eat the berries.

Sure David - I am acutely aware of the beneficial effects. However we're
talking "balance of nature" here, and I want to restore some of the
balance lost when agricultural workers left the land. [1]

John

[1] Most of them for the cities, and the rest, for their tractor cabs! I
don't begrudge them their tractors one whit, in particular as their
numbers are a tiny fraction of what they used to be. However there are a
million small jobs that used to be done on the land which now never even
get considered: keeping the ivy off major trees is one such. And there's
***plenty*** of ivy elsewhere, by golly!

On 05/05/2014 22:11, Another John wrote:
In article ,
David Hill wrote:

My question: is there any truth in the old saw that ivy, once securely
established on a tree, will become genuinely parasitic, and will draw
sustenance from the tree itself?

None at all. The greatest danger is that the ivy will increase windage
on the tree and may cause its downfall during gales, esp. following wet
weather.

On the other hand tie ivy was providing shelter and food for a number of
birds and insects
€Holly blue caterpillar feeds on the flowers buds.
€Wasps, hornets, hoverflies, bumblebees, red admirals, small
tortoiseshells and peacock butterflies, and other late-flying insects,
drink the nectar.
€Many birds, such as blackbirds and thrushes, eat the berries.

Sure David - I am acutely aware of the beneficial effects. However we're
talking "balance of nature" here, and I want to restore some of the
balance lost when agricultural workers left the land. [1]

John

[1] Most of them for the cities, and the rest, for their tractor cabs! I
don't begrudge them their tractors one whit, in particular as their
numbers are a tiny fraction of what they used to be. However there are a
million small jobs that used to be done on the land which now never even
get considered: keeping the ivy off major trees is one such. And there's
***plenty*** of ivy elsewhere, by golly!


You might find this item of interest
http://www.arborecology.co.uk/article_forf.htm

In article ],
Another John wrote:

My question: is there any truth in the old saw that ivy, once securely
established on a tree, will become genuinely parasitic, and will draw
sustenance from the tree itself?

No.


I agree I cut through loads when we first bough this house, it all died.
But, 11 years later dead ivy is still falling from high up in the trees.

Mike

On 05/05/2014 22:49, David Hill wrote:
On 05/05/2014 22:11, Another John wrote:
In article ,
David Hill wrote:

My question: is there any truth in the old saw that ivy, once securely
established on a tree, will become genuinely parasitic, and will draw
sustenance from the tree itself?

None at all. The greatest danger is that the ivy will increase windage
on the tree and may cause its downfall during gales, esp. following wet
weather.

You might find this item of interest
http://www.arborecology.co.uk/article_forf.htm

An interesting article, although it doesn't mention ivy on conifers.

Although I would never expect ivy to act like a strangler fig, I
sometimes wonder if excessive coverage inhibits tree growth. Also, does
it weaken the wood or strengthen it? Old ivy "wood" seems quite tough
to me, requiring several strikes with an axe to sever it. So does it add
support to a tree, and if so does the tree react by not needing to
llignify quite to much to support its own weight? Or is the ivy just
added weight, so the tree then needs additional lignification to support
the weight of the ivy as well as its own weight?

--

Jeff

In article ,
Jeff Layman wrote:

On 05/05/2014 22:49, David Hill wrote:
....
You might find this item of interest
http://www.arborecology.co.uk/article_forf.htm

An interesting article, although it doesn't mention ivy on conifers.

Yes - interesting, and provides answers (presumably accurate ones) to
all the questions I had (as well as the one I actually asked, which was:
does mature ivy morph into parasitic growth on trees? Answer: No.).

Jeff also said:

Although I would never expect ivy to act like a strangler fig, I
sometimes wonder if excessive coverage inhibits tree growth. ...

It does. I have dealt with ivy in a very large hawthorn hedge, where it
had been allowed to grow unrestricted for many, many years. Some of the
ivy stems were 4 to 6 inches thick; where they had twisted round the
hawthorn trunks, the trees were dying; further, the thick masses of ivy
"undergrowth" in the hedge tops had caused the host wood to rot, through
debris accruing year, on year, on year, getting wet, and rotting down: a
hedge bottom in the hedge top, in fact.

I would never eradicate ivy (you couldn't, anyway!), because of the good
that it does (listed in that article); but it's an awful bully, and
needs keeping strictly in check. In my humble opinion.

J.

In article ],
Another John writes
In article ,
Jeff Layman wrote:

On 05/05/2014 22:49, David Hill wrote:
....
You might find this item of interest
http://www.arborecology.co.uk/article_forf.htm

An interesting article, although it doesn't mention ivy on conifers.

Yes - interesting, and provides answers (presumably accurate ones) to
all the questions I had (as well as the one I actually asked, which was:
does mature ivy morph into parasitic growth on trees? Answer: No.).

Jeff also said:

Although I would never expect ivy to act like a strangler fig, I
sometimes wonder if excessive coverage inhibits tree growth. ...

It does. I have dealt with ivy in a very large hawthorn hedge, where it
had been allowed to grow unrestricted for many, many years. Some of the
ivy stems were 4 to 6 inches thick; where they had twisted round the
hawthorn trunks, the trees were dying; further, the thick masses of ivy
"undergrowth" in the hedge tops had caused the host wood to rot, through
debris accruing year, on year, on year, getting wet, and rotting down: a
hedge bottom in the hedge top, in fact.

I would never eradicate ivy (you couldn't, anyway!), because of the good
that it does (listed in that article); but it's an awful bully, and
needs keeping strictly in check. In my humble opinion.

J.

We have a hedge, mainly hawthorn and field maple, in a rural setting that I
have been been cutting for nearly 40 years. The hedge has been there at least
twice as long as that. To begin with I left the ivy alone persuaded by the
comments in gardening programmes that it is a natural resource.

But then I noticed that when a plant died no replacement grew, you are supposed
to be able to estimate the age of a hege by the number of species in it, right?
I reckon the ivy was to blame so I started clearing it on a rolling basis,
starting at both ends and working to the middle. This seems to work as I do mot
have to plant new bushes where I have cleared the ivy.

There is still a small section in the middle (about three yards long) where I
leave more ivy. This is where the birds mostly nest and where they retreat when
disturbed. So like many things it seems a compromise and there is no absolute
right way to do it, just the different ways that suit you (and me) best.

I found the DEFRA website helpful, for example:
http://archive.defra.gov.uk/foodfarm...ws.htm#mainten
ance

--
Ellis Morgan

In article ,
Ellis Morgan wrote:

http://archive.defra.gov.uk/foodfarm...ows.htm#mainte
nance

That looks a great reference -- thanks Ellis.

J.