Climate warming is likely to cause differential shifts in the phenology of pollinators and nectar sources. Detection of these shifts requires careful observation of emergence and peak populations of both the animals and plants involved. On salt marshes of Canada's Chaleur Bay, the potential for asynchronous appearance of the adults of the endangered butterfly Coenonympha nipisiquit (Maritime Ringlet) and its primary nectar sources has become a concern. We used citizen scientists and simple equipment to collect field observations of blooming of key nectar sources: Lysimachia maritima (= Glaux maritima) (Sea Milkwort), Limonium carolinianum (Sea Lavender, Carolina Sea Lavender, or American Thrift), and Solidago sempervirens (Seaside Goldenrod). These species have distinctly different flowering architectures that present varied challenges to observations of initiation of blooming and peak blossoming; therefore, our results have value to a diversity of environments. We show how techniques of remote sensing can be applied to analyze photographs collected by citizen scientists, thus providing records of peak blooming and eliminating observer bias. The success of photographic monitoring depends upon floral architecture and simple shading to prevent oversaturation of sunlight.