[rainie]

Hope this is in the right place.

I have a 25/30ft monkey puzzle in my front garden, almost overnight it has begun to go brown on its trunk and the branches near the trunk, leaving (at the moment) the other half of the  branches furthest from the trunk green.

Our village is built on lime and iron stone. We also have clay.

Any ideas why and can it be saved?

The lower trunk has almost always leaked a whitish gluey sap (we have known the tree for 7yrs)

Is this a honey fungus?

In the spring we lost 2 young eucalyptus trees, we presumed to the cold winter. Also in the front garden. Neighbours lost theirs too.

[sunshineband]

Monkey puzzles sometimes end up with brown sections where their leaves are dying back, giving the impression a whole branch is dying.

They don't usually suffer from diseases although recently there has been a completely new pathogen discovered that affects the roots of stone pines and eucalyptus. Given that where you are the winters are not mild, I would think that the loss of eucalyptus was due to two years of hard weather though, rather than a newly discovered pathogen. 

With your monkey puzzle, it would be worth giving it a good feed/mulch of well rotted manure to help it along.

Is there a wound near where it leaks sap? Or are there scale insects on the trunk at this point? Either could be responsible.

Sorry not to be more helpful