"Ronald Green" wrote:

Hello Ronald

RG I have a very large Spruce tree in a garden that I am
RG looking after. The tree has a large hole about the size of a
RG Rugby Ball in one of the branches.
RG If we have a bad storm the branch may collapse causing
RG damage to a Tennis Court.
RG The owner does not want to remove the branch, preferring to
RG fill the hole and wedge the branch so that it will not fall.

Not a good plan. Propping /can/ work, but only for relatively short
branches and ONLY where it's sheltered. In a storm the whole tree
moves an awful lot and any propping is gonna fall away. Looks
ridiculous too, although for heavy cropping fruit trees it can be
temporarily neccessary.

RG Would anyone be able to recommend a non-toxic tree filler
RG and supplier?

Why would you fill the hole? Just in case this isn't a troll - filling
the hole will achieve precisely nothing, won't add anything to the
strength and is likely to induce even more rot.

The only viable solution, if it is dangerous, is to remove it, or at
least shorten the branch so that there isn't enough weight on that
fault to cause failure.

--
Simon Avery, Dartmoor, UK Ý http://www.digdilem.org/