Crews were called to the scene around 1.45pm and managed to get the fire under control in about an hour.
An emergency warning was issued to residents, however District 12 Rostered Duty Officer Brian Wright downgraded the warning to a Watch and Act, thanks to the quick work of firefighters.
"The cause seems to be suspicious so we're working with Victoria Police to determine how the fire started," Mr Wright said.
"Fences of about 20 homes were damaged, however crews were able to protect homes in the area."
The fire spread to about three hectares.
Brigades including Craigieburn, Darraweit Gum, Epping, Kal Kallo, Kilmore, Wallen, Wandong, Whittlesea and Wollert attended.