Pollinator seed mixes are phenologically dissimilar to prairie remnants

Native seed mixes are widely available to create pollinator habitat. One approach to understand the efficacy of pollinator seed mixes is to compare them to species found in high-quality natural areas. Using plant species presence data from published lists, we compared weekly blooming richness between 196 seed mixes explicitly designed to support pollinators and 102 prairie remnants from eight states across the Midwest. Remnants had greater forb richness compared to mixes and had at least twice the blooming richness per week. Seed mixes included low proportions of species that bloomed in the spring (0–13% of species), whereas about 28% of remnant forbs bloomed before June. There was a sharp phenological blooming peak for mixes due to the vast majority of species blooming in late July through August, whereas remnants had greater phenological evenness across the growing season. We then investigated all observed early blooming plant species to identify the species best suited to alleviate the dissimilar spring blooming characteristics. We compiled 10 species characteristics that reflected species' feasibility for cultivation and restoration and blooming attributes, identifying a group of underutilized and commercially unavailable species. Pollinator seed mixes should facilitate blooming availability for the duration of the growing season to meet pollinator foraging requirements.