<p><i>Erwinia amylovora</i> is one of the most economically impactful plant pathogens worldwide. Pruning infected shoots and/or cankers throughout the season is commonly used to reduce the amount of inoculum present in the field. However, if the infection is not removed completely or pruning tools are not disinfected thoroughly, cutting wound infection can develop and spread, leading to tree death. Copper, a widely used chemical with bactericidal activity, is commonly used to manage fire blight. In this study, we investigated the efficacy of copper alone and/or mixed with latex paint to protect cut wounds from infection. Our results showed that copper itself and latex paint can provide some protection against <i>E. amylovora</i> infection when applied directly to cut wounds prior to inoculation. A 55–70% decrease in trees displaying symptoms was observed in the 2022 trial for copper itself and latex paint. Our results also showed, on average, 88% shorter necrotic lesions with copper treatment as compared to the control. In contrast, 100% of the trees displayed symptoms during both 2022 and 2023 when treatments were applied post-inoculation. Most significantly, trees treated with copper in latex paint and applied post inoculation had 70–109% longer necrotic lesions than those of the control. Our results indicated that, when applied prior to the development of an infection, copper itself and latex paint could provide some protection against fire blight disease.</p>