"Heidi the Horrible" wrote in message ...
The way I understand it, the injections are useless when root grafting
occurs from a nearby infected tree.

Our arborist told us the tree lived so long because it was isolated from
other elms. Elms in a pack have no chance.

HtH

And doesn't Dutch elm disease take quite a number of years to kill
trees? I recall trees slowly dying over many years here in NJ when I
was a kid. It seems unlikely to me that missing injections from a
couple years ago could lead to the total demise of the tree that
quickly.