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.
Tens of millions to be invested in Devon's buses
Local leaders will decided how money is spent
Fawlty Towers: The Play - REVIEW
Chaotic tribute act to renowned series
Lib Dems hold Exmouth seat in by-election
Fran McElhone wins the Halsdon seat
Paignton YMCA moves into former Mormon chapel
Our new home is absolutely ideal'
Homes to be built on former Exeter driving range
More than 50 houses planned
Extra staff to improve adult response times
Two-day target only hit in one in every 10
