In article ,
john brook wrote:

Ivy grew up my ash trees. No sign it's harmed them. Ivy is great for
birds, they hide in it from cold and some nest in it.

Apart from looking unsightly to some, it can cause damage to the tree from
high winds. the tree calculates how strong to make its branches to a fine
degree and doesnt allow for the added *wind- resistance* of ivy. you
often
see broken branches from ivy infested trees.

That applies only when it gets out into the canopy. Even a thick
coat of ivy on the trunk and main branches will not harm a healthy
tree (or most unhealthy ones, for that matter).

if you look for them it may surprise to see how very thick main branches are
brought down.

Sigh. That's irrelevant, as you should remember from your school
days (elementary physics).

It is as much a matter of leverage as quantity. Ivy IN THE CANOPY
can break quite large branches, but ivy ON JUST THE MAIN BRANCHES
will do so only if they are already completely rotten.


Regards,
Nick Maclaren.