The fires have been on farmland in areas around Newton Abbot, Teignmouth, Paignton and Dawlish.
All the incidents involved a number of fire crews attending the scenes for long periods of time.
Safety advice has now been issued to farmers on how to reduce the risk of arson, including preventing easy access and installing security.
Man on a mission to bring Plymouth alive at night
Lack of things to do after 7pm
Quick build homes not so swift
Delays hamper completion in Mid Devon village
New gadget to thwart Paignton seafront car pests
Anti-social driving has been blighting the area for some time'
East Devon cliff fall site still under scrutiny
The fall at Beer has been investigated
Exeter's new waste recycling plant to cost £13 million
New building will be cheaper than modernising existing plant
20 homes for Torridge village proposed
40% will be affordable
