More than 350 ash saplings were burnt in Bicester on Monday after signs of a deadly fungal disease were spotted at the end of last week.
The saplings had been planted at the new Kingsmere estate in south-west Bicester.
A spokesman for Kingsmere developer Countryside Properties said contractors acted immediately to remove and burn the trees once the chalara fraxinea fungus was detected.
He added: “All the diseased trees have been taken out and burnt.
“We’ve left in 60 more mature ash trees that are not affected at the moment.
“The main thing is we’ve got every single diseased tree out and burnt.”
He said there had not yet been a calculation of the cost of the damage caused by the outbreak, but said any replacement trees would have to be agreed in a joint decision with Cherwell District Council.
The 60 mature ash trees planted at Kingsmere, which are not currently affected, may have to be removed and destroyed in future, the spokesman said.
He added: “We’ve done a lot of planting over the last three years.
“Some trees are mature, and we hope they will be unaffected, but with the small ones there was no point in leaving them in.”
More than 130 sites across Britain have been affected.