Plants treated with diverse species of fungi that live on roots grew larger flowers, prompting bees to visit them more often and spend more time there.

“[These fungi] might not only have benefits for the plant itself, or for the soil, but also for the pollinators,” says Aidee Guzman at Stanford University in California.

Guzman and her colleagues grew squash plants (Cucurbita pepo) inoculated with four combinations of different species of mycorrhizal fungi. These fungi live on…