Natural Lawn Care
Here are some articles on how to care for your lawn in a more natural way:
Chicago-area companies that offer environmentally friendly services
http://www.nl-amer.com/
http://www.richsoil.com/lawn-care.jsp
http://www.spcpweb.org/yards/
Invasive Species
Some of the plants in your yard are not native to northern Illinois. Here are some sites to help you identify invasive species:
http://www.chicagobotanic.org/research/conservation/invasive/chicago/
http://www.invasivespeciesinfo.gov/unitedstates/il.shtml
http://dnr.state.il.us/orep/ctap/invasive/
http://www.cod.edu/visitors/prairie/invasive_species.htm
http://na.fs.fed.us/spfo/invasiveplants/states/il.asp