There are currently 100 sheep grazing at Sheepcote Valley
A scheme in Brighton where sheep are used to keep grass short instead of lawnmowers will be expanded.
The animals are used in Moulsecoomb Wild Park, Bevendean Down and Sheepcote Valley with volunteer urban shepherds recruited to look after them.
Now Brighton and Hove City Council will double the number of sheep at some existing sites as well as extending the scheme to Whitehawk Hill.
The plans were approved by councillors at a meeting on Thursday.
The council said using the animals was more natural and traditional.
Sheep have been allowed on some publicly-owned open spaces in the city for 10 years.
They are from a local farm and graze for periods during the winter months.
Councillor Geoffrey Theobald said: "Using sheep instead of mowers is a much better way of keeping the grass down on our chalk downland sites which are rich in wildlife.
"Sheep are a much more natural and traditional way of cutting the grass and they have being doing the job for centuries on this sort of grassland.
"They graze selectively, munching and eating things at different heights and that creates different microclimates to help wildlife flourish."
A team of 65 urban shepherds help to keep watch on sheep in the city.
They attend a free training course with a local shepherd and are invited to join a sheep watching rota.
At the moment there are 100 sheep grazing at Sheepcote Valley, which the council will now double.