A slow-moving bushfire is burning out of control in central Victoria.

The CFA has issued a watch and act message for the 50-hectare fire in Tallarook, 100km north of Melbourne.

The fire is burning in the area of Landscape Road, close to a few farming properties.

An incident control centre spokeswoman says the fire is in difficult terrain and aircraft will begin an aerial attack mid-morning.

"The terrain is actually really, really steep so it's difficult for crews on foot to access," she said.

People in the area are being urged to follow their bushfire survival plans.