Botany for Gardeners. Revised Ed. Brian Capon (Timber Press, 2005).
Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens. Douglas W. Tallamy (Timber Press, 2007).
Food Not Lawns: How to Turn Your Yard into a Garden And Your Neighborhood into a Community. H. C. Flores (Chelsea Green, 2006). A gardening book for radical gardeners. Some people are put off by its "preachiness," but not me. Like Gaia's Garden, Oregon-centric, so not all advice is not practical for our region.
Gaia's Garden, Second Edition: A Guide To Home-Scale Permaculture. Toby Hemenway (Chelsea Green, 2009). A classic. Good advice on methods, though West Coast-centric so not all recommendations are suitable for the Midwest.
Land of Big Rivers: French and Indian Illinois, 1699-1778. M. J. Morgan (Southern Illinois University Press, 2010). Environmental history of the land and peoples along the Mississippi between the Missouri and the Ohio Rivers.
Landscaping With Native Trees. Jim Wilson and Guy Sternberg (Houghton Mifflin, 1995). An outstanding book with excellent photographs and informative text.
A Natural History of the Chicago Region. Joel R. Greenberg (University of Chicago Press, 2002).
Native Trees for North American Landscapes. Guy Sternberg and Jim Wilson (Timber Press, 2004). Updated and more complete and in depth than Landscaping with Native Trees.
Nature's Metropolis: Chicago and the Great West. William Cronon (W.W. Norton, 1992).
Plants of the Chicago Region. 4th Ed. Floyd Swink and Gerould Wilhelm (Indiana Academy of Sciences, 1994).
Of Prairie, Woods, and Water: Two Centuries of Chicago Nature Writing. Ed. Joel Greenberg (University of Chicago Press, 2008).
The Prairie Spirit in Landscape Gardening. Wilhelm Miller (University of Illinois, 1915; Reprint edition, University of Massachusetts, August, 2002). Old yet timely advice by the man who invented the term "prairie style" as he advocated for using native plants and naturalistic designs.
A Sand County Almanac (Outdoor Essays and Reflections). Aldo Leopold (Ballantine, 1986). There are several available editions of this seminal work by one of the foremost American conservationists. These essays distil his thought in poetic fashion. A life-changing book.
Secrets to Great Soil. Elizabeth Stell (Storey Publishing, 1998). How-to with simple instructions.
Thinking in Systems: A Primer. Donella Meadows (Chelsea Green, 2008). Ever wonder about why an ecosystem is called that? What a feedback loop is? This book explains how system theory works, in clear language with good diagrams.
Win-Win Ecology. Michael L. Rozensweig. (Oxford University Press, 2003).
Wildflowers: A Guide to Growing and Propagating Native Flowers of North America. William Cullina. (Houghton Miflin, 2000). Just what the title says. Very informative, well organized, clearly written.
Wild Ones Handbook: A Voice for the Natural landscaping Movement. Ed. Joy Buslaff. (Wild Ones—Natural landscapers Ltd., 1997). A useful guide to gardening with native plants.