Keep the weeds in the lawn?

When I was a kid, my mother would give me a kitchen knife to dig dandelions out of the lawn. Now it seems that I should have left them. Sarah Lovell and Douglas Johnston state in their 2009 paper in Ecology and Science that residential yards can have a role to play in contributing to ecological function, especially those that have a range of environments (shrubs, trees, ponds, grassy areas, etc.). Take the common lawn. Herbicided and clipped lawns contribute little to biodiversity but weedy lawns can enrich it. Lovell and Johnston state that "a simple example of a site-level opportunity for improving biodiversity in a residential area is the replacement of a conventional turf lawn with a  mix of prairie species." If you don't want to replace the lawn, some plants are perfectly suited to co-existing with turf and lawnmowers, including plantain, lyreleaf sage (Salvia lyrata), and spring beauty (Claytonia virginica). These early spring wildflowers can be overseeded into a lawn if you don't have them. How do you manage for them? Simply don't mow for a while until they are finished blooming and have set seed.