Biological invasions of non-native species are an important conservation issue because of the potential negative impacts on native plant and animal communities. One species of concern in Virginia is Japanese spiraea (Spiraea japonica L.f.). At Buffalo Mountain Natural Area Preserve (BMNAP) the spread of Japanese spiraea threatens the integrity of native high-elevation grassy balds, eastern redcedar (Juniperus virginiana L.) glades, and mafic seep communities. A prerequisite to successful management of a non-native species is knowledge about where a species has established and how it spreads. Thus, our objectives were to: (1) identify current populations of Japanese spiraea at BMNAP, and (2) characterize environmental conditions favoring the growth of Japanese spiraea. Paired-plot sampling was used to compare environmental parameters from adjacent plots with and without Japanese spiraea. Canopy cover was significantly lower in plots with Japanese spiraea compared to plots without Japanese spiraea (t = 1.76, P = 0.02), suggesting Japanese spiraea is more successful in establishing in higher light environments. At BMNAP, lower canopy cover reflected historical disturbances such as old power line cuts or roads. Although Japanese spiraea is not currently invading the grassy balds or eastern redcedar glades at the Buffalo Mountain summit, existing populations pose an immediate threat to the mafic seeps at the base of the mountain. Regular monitoring and mapping will be important to prevent Japanese spiraea from hindering conservation goals.