About six hectares (14.83 acres) of the Ridgeway will be covered with seeds
Work to plant grass and wildflowers along Dorset's controversial £87m Weymouth relief road is under way.
Local species of plants have been chosen for the road, which is being built between Dorchester and Weymouth ahead of the 2012 Olympics.
The road cuts through a chalk and limestone Ridgeway and the aim is to cover land exposed during the work.
About six hectares (14.83 acres) will be covered and Dorset varieties are being used where possible.
However some seeds are coming from Somerset or other parts of southern England.
Grazed by animals
Dr Phil Sterling, Dorset County Council's natural environment manager, said: "It could take as little as a month for the green shoots to show or we may have to wait until late spring, it really depends on the weather and how mild it is.
"This summer the wildflowers will just be establishing. By summer 2011, they should be flowering well and provide a fantastic display."
The Ridgeway slopes will have a fence around them, so in the long-term they can be grazed by animals to maintain the wildflowers.
The controversial £87m new route between Weymouth and Dorchester is set to improve access to Weymouth and Portland ahead of the 2012 Olympic sailing events.
The new road is set to open in 2011 but Skanska, which is building the road, said it may open by late 2010.
The site attracted interest after archaeologists found an ancient burial pit containing the 51 decapitated skeletons of Viking warriors.