Seeds from the trees will be harvested to be propogated into advanced tube stock for trees to be grown nearby after the roadworks are completed.

The affected trees are located in a strip of land measuring 20 metres wide by 280 metres long.

The new road will link Anson Street to Pinnacle Road.

The tree area affected is near Sundew Circuit.

Orange City Council has engaged horticulturist Bill Josh of Habitat Connect for the work.

Mr Josh will propagate trees including Apple Box and Ribbon Gum.

He has been propagating native grasses, flowers and trees in the region over many years.

Mr Josh has completed a similar project with another vulnerable species, Black Gum, at Perthville for Bathurst Regional Council.

Mr Josh has been harvesting the Orange seeds this month.

He will continue to gather seeds until the work on Stage 4 gets underway, which is expected next year.

Mr Josh said he expected to collect thousands of seeds.

"The best time to harvest the seeds is after a storm or a strong wind when the branches have been blown off, you can just go and collect them off the ground," he said.

"I like to harvest them when the seed pods are ready to go and take them back to my nursery where I allow them to dry out slowly.

"I get a lot more success with germination that way."

The initial work by Mr Josh will involve propagating 100 trees.

That process will take about 12 months.

The remainder of the seeds will be stored and used for other council projects throughout the Orange area.

Orange Mayor Reg Kidd said the propagation exercise was a condition of the approval of the Stage 4 work.

The Review of Environmental Factors into the project identified endemic species that were part of the Tablelands Snow Gum Woodlands Ecologically Endangered Community.

"Council wanted to ensure the impacts of the project on the environment were properly considered and adequate measures were taken to mitigate the effect of the Southern Feeder Road on these native tree species," he said.