Let me put on my devil's advocate hat, and suggest that wildflower
planting is not an unmitigated good.
Consider a program in my own state, which advocates using native
prairie vegetation in roadside ditches to cut maintainance costs
associated with mowing, herbicide spraying, etc., and at the same
time gives more wildlife habitat. It also makes for much prettier
and more diverse ditches in a state that has lost about 95% of its
native plant acreage.