We evaluated whether plantings of sunflower (Helianthus annuus), whose pollen reduces infection by some pathogens when fed to bees in captivity, lowered pathogen levels and increased reproduction in free-foraging bumble bee colonies (Bombus impatiens). We placed pairs of commercial colonies of B. impatiens at 20 mixed vegetable farms in western Massachusetts between Jul-23 and Oct-6 2019. Flowering resources typically visited by bumble bees were quantified at each farm twice to characterize abundance and diversity. We also visited each farm 3-4 times and at each visit, we (a) recorded colony weights to track growth, (b) collected ~10 corbicular loads from returning foragers (per site) to assess usage of sunflower and other Asteraceae, and (c) collected 10 returning foraging workers from each colony entrance for later pathogen analysis. Visual assessment of pathogen samples and pollen composition occurred at UMass Amherst during the 2019-20 academic year. Molecular assessment of pathogen samples occurred at UC Riverside. An associated manuscript with this title and these authors is being submitted for publication.