The historic Farley's oak in Greytown is safe for another year.
The latest arborist report shows that despite fighting a fungal disease, the oak's health is improving.
In 2012, the 150-year-old tree was going to be felled after arborist reports said it was unlikely to survive but the Farley family, descendants of the settlers who bought the section on which the oak was planted, doubted the inspection results.
South Wairarapa District Council then opted to monitor and maintain the tree instead, with annual arborist reports. The latest report was tabled last week at a Greytown Community Board meeting.
Farley family descendant and board member Ian Farley was pleased to hear the tree was doing well.
"The tree isn't declining anymore," he said.
Council contractor City Care had been maintaining it, which appeared to be working.
Dave Aitchison, of Arbortech Services, said in his report to council that the tree's overall health had improved, thanks to favourable growing conditions over the last two seasons and remedial work.
He said the decline and dieback of the upper canopy had stopped and there was vigorous regrowth.
"The new growths will help to sustain the tree and make its survival more viable, particularly in helping to promote new roots and improve resistance to ongoing fungal pathogen attack."
Mr Aitchison had noticed honey fungus growths at the base of the main trunk, which had also been there last year but in a different spot.
This was due to the recent wet and humid conditions - ideal growing conditions for mushrooms.
Mr Aitchison said it couldn't accurately be determined if the tree's roots were infected by the fungus but the increase in the canopy growth over the last four years indicated the rooting system was improving.
There were "no significant hazards" and, overall, the oak was safe.
"The overall structural integrity and stability of this tree does not appear to be compromised."
Mr Aitchison said continued maintenance would ensure it kept improving.