The largest was a 30-hectare blaze at Springhill on Sunday and scrub fires also threatened property at Porcupine Ridge and Yandoit last Thursday.

While the cause of the fires is yet to be determined, Daylesford police say they can't rule out the possibility that a firebug is operating in the region.

The fire near Springhill started about 2.30pm and was under control by about 4pm with no lives endangered or property damaged.

Country Fire Authority duty officer Archie Conroy said more than 20 fire fighting vehicles from the CFA and Department of Sustainability and Environment and 100 personnel fought the fire, which broke out along the

Trentham/Springhill Road Sunday afternoon.

A fire fighting aircraft helped control the scrub fire at Porcupine Ridge. DSE tankers and bulldozers were also used.

About two hectares of grassland caught fire on a private property but fire crews stopped the blaze spreading to a home and a pine plantation on Porcupine Ridge Rd.

A Porcupine Ridge resident, who didn't want to be named, said he was convinced the blazes were the work of a firebug.

"Somebody out their obviously doesn't have a brain in their head. It seemed someone was going along lighting fires for the day," he said.

The man claimed two smaller fires were also lit but failed to take hold in the surrounding bush.

He said he felt for neighbours who came perilously close to losing their homes.

"It was very lucky the houses weren't lost. People had to sit and watch the flames approaching their houses," he said.

The fire started at 3.30pm and was under control by 4pm.

Residents were forced to wait about 20 minutes as crews from Daylesford and Hepburn Springs directed the fire away from houses and sheds.

Mr Conroy said the dry conditions caused the blaze to spread quickly.

"It is under investigation at this stage, we are still trying to find out, but it is in a remote area so we are not sure if it is human error or deliberate at this stage," Mr Conroy said.

A separate fire also threatened several homes and sheds at Yandoit on Thursday night.

About 100 firefighters from the CFA and DSE worked to contain the blaze in about half-an-hour. Three hectares of grassland on a private property were burnt.

Daylesford Sergeant Andrew Guiney urged residents to report all fires no matter how small.