Strategies that support bee health and benefit growers are needed for sustainable pollinator management in agroecosystems. Floral resources are important for bee nutrition, and can also have antiparasitic effects. In previous work, pollen diets from sunflowers and other Asteraceae species in laboratory bioassays significantly decreased infection by the bumble bee gut pathogen, Crithidia bombi, in the common eastern bumble bee, Bombus impatiens. However, it is unclear if this pattern holds in the field, where bumble bees may have mixed rather than monofloral diets, and how broadly Asteraceae pollen reduces infection. We investigated whether pollen from other cultivated and wild Asteraceae species reduces C. bombi infection on farms and in laboratory bioassays. We surveyed wild and cultivated Asteraceae floral abundance and C. bombi infection in free-flying B. impatiens workers on six farms in Massachusetts, USA growing varying amounts of cultivated Asteraceae flowers. We also collected and sorted honey bee pollen pellets to conduct laboratory bioassays testing the effect of mixed Asteraceae pollen on B. impatiens workers inoculated with C. bombi. On farms, we found no significant relationship between cultivated or wild Asteraceae floral abundance and C. bombi infection in B. impatiens workers. In bioassays, four out of five Asteraceae diet significantly reduced C. bombi infection compared to buckwheat pollen (Fagopyrum esculentum) as a negative control. This study expands the list of Asteraceae whose pollen reduces C. bombi infections in B. impatiens in the laboratory. However, under field conditions, flowering Asteraceae did not to reduce infections in local B. impatiens populations.