Managing invasive species in natural areas of high ecological value generally involves the selection of an appropriate control method that is cost effective while minimizing the secondary impacts of the control operation on the ecosystem. During the last decades, speckled alder (Alnus incana ssp. rugosa) has been invading wet sedge meadows of the Lac Saint-François National Wildlife Area (NWA), Québec, Canada. This invasion threatens the habitat of several bird and plant species considered rare at the national and provincial levels. We evaluated effectiveness and impacts of four methods for controlling alder invasion in the wetland. As a short-term control method, controlled fire appears to be ineffective in the context of the Lac Saint-François NWA, as suggested by the high survival of alders in a zone previously burnt on our study site. Double-cut of the shoots aims at killing the shrubs by depleting nutrient reserves in the roots using two successive cuts during the same growing season. This method was also shown to be ineffective: more than 80% of the treated alders resprouted vigorously the following year. Foliar application of herbicide with a rope-wick applicator to control smaller shrubs did kill all treated individuals. However, this method showed high risks of herbicide dripping and should be used with care. The most promising control method was the herbicide treatment of cut stumps. This method was efficient and cheap. It was also efficient at the end of winter, when the ground of the wetland was still frozen, which facilitated accessibility and limited damages to non-target species caused by trampling or herbicide dripping.