Over the last 20 years, the exotic invasive genotype of common reed (Phragmites australis [Cav.] Trin. ex Steud.) has been gradually spreading across the Marais-Léon-Provancher Nature Reserve (Québec, Canada), a 125-ha site, comprising a 14-ha freshwater marsh. Field surveys conducted from 2013 to 2015 identified and mapped 41 colonies in the marsh. Given the environmental conditions and site accessibility, 5 control methods were used to control common reed expansion: hand-pulling, mowing, tarping, mechanical excavation with seeding, and the planting of competitive plant species. In 2013, the combined surface area of the colonies was 7579 m2. By 2017, this had been reduced by 19.1% to 6132 m2. Mechanical excavation with seeding, hand-pulling and tarping resulted in large reductions in common reed patch size (decreases of 99%, 88% and 47%, respectively), while mowing and the use of plant competition were less effective (reduction of 28% at best).