Seeding density of wildflower mixes affects nectar production in a focal plant species

Abstract

Restoring habitat with diverse flowering plants is an important tool for pollinator conservation. Pollinator-friendly seed mixes used in restorations vary in seeding density and forb-to-grass seed ratio, but few studies have examined the potential differences in nectar quantity and quality produced among mixes. We quantified the nectar rewards of Penstemon digitalis in plots planted with seed mixes of varying seeding density and forb-to-grass ratios by measuring nectar volume and sugar concentration. We found that nectar sugar concentration of P. digitalis was greatest at low seeding density, suggesting pollinator support in low-cost seed mixes. Understanding how seed mix design parameters impact pollinator food resources is a key next step in habitat restoration for pollinator conservation.