They need habitat, and small sites do matter. Here is some pretty good information for homeowners, however, I prefer to specify natives only. If everyone put in a garden like this, it would really have great positive impact.
I do see butterflies in the urban gardens and industrial/corporate sites we have been working on.
FYI – a few more facts.
I was struck once again with the lack of flowers on my back-road drive to Peoria last week. We can do better. We can replant our native plants. We can co-exist, and we all will thrive when nature thrives.
http://chicago.suntimes.com/opinion/monarch-butterflies-need-help-in-illinois/
https://illinois.sierraclub.org/priorities/monarchbutterflies
https://monarchjointventure.org/
The best thing we can all do is plant more habitat – more natives!
Re-Ecology Land Design 