| | Brian Capon | Timber Press | All; 1 | |
| | Donna N. Schumann, Elwood B. Ehrle, and Richard W. Pippen | Mad River Press | All; 1 | |
| | Robert E. Gough | The Haworth Press | All; 1 | |
| | Thomas L. Rost, Michael G. Barbour, C. Ralph Stocking, and Terence M. Murphy | Wadsworth | All; 1 | |
| | James D. Mauseth | Jones & Bartlett Publishers | All; 1 | |
| | John E. Preece and Paul E Read | John Wiley and Sons | All; 1 | |
| | George Acquaah | Prentice Hall | All; 1 | |
| | Laura Williams Rice and Robert P. Rice | Prentice Hall | All; 1 | |
| | David Attenborough | Princeton University Press | All; 1 | |
| | Angela Overy | Fulcrum Publishing | All; 1 | |
| http://www.ianrpubs.unl.edu/epublic/live/ec1259/build/ec1259.pdf | Anne M Streich | University of Nebraska-Lincoln Extension | All; 1 | |
| http://www.ianrpubs.unl.edu/epublic/live/ec1257/build/ec1257.pdf | Anne M Streich | University of Nebraska-Lincoln Extension | All; 1 | |
| http://www.ianrpubs.unl.edu/epublic/live/ec1258/build/ec1258.pdf | Anne M Streich | University of Nebraska-Lincoln Extension | All; 1 | |
| http://www.cactusmuseum.com/survival.asp | | Cactus Museum | All; 1 | |
| http://wc.pima.edu/Bfiero/tucsonecology/plants/plants_photosynthesis.htm | | Pima Community College | All; 1 | |
| http://www.ahs.org/publications/heat_zone_map.htm | | American Horticultural Society | All; 1 | |
| http://www.sunset.com/garden/climate-zones | | Sunset magazine | All; 1 | |
| | Grace Gershuny | Rodale Press | All; 2; 7 | |
| | Elizabeth P. Stell | Storey Communications, Inc | All; 2; 7 | |
| | Helmut Kohnke and D. P. Franzmeier | Waveland Press | All; 2 | |
| http://soils.usda.gov/education | | USDA Natural Resources Conservation Service | All; 2 | |
| http://websoilsurvey.nrcs.usda.gov/app | | USDA Natural Resources Conservation Service | All; 2 | |
| http://soils.usda.gov/survey/printed_surveys/state.asp?state=Indiana&abbr=IN | | USDA National Resources Conservation Service | All; 2 | |
| download here (free but large) or purchase book | Fred Magdoff and Harold van Es | Sustainable Agriculture Research and Education Program (SARE) | All; 2 | |
| http://www.ag.purdue.edu/agry/extension/Pages/soil-testing-labs.aspx | | Purdue Agronomy Extension | All; 2; 6 | |
| http://mdc.itap.purdue.edu/item.asp?item_number=HO-71-W | Michael N. Dana and B. Rosie Lerner | Purdue Extension | All; 2; 6 | |
| http://www.extension.umn.edu/distribution/horticulture/components/M1228.pdf | Jill MacKensie | University of Minnesota Extension | All; 2 | |
| Order publication here | Preston Sullivan | National Sustainable Agriculture Information Service | All; 2 | |
| http://mdc.itap.purdue.edu/item.asp?item_number=HO-222-W | Michael N. Dana and B. Rosie Lerner | Purdue Extension | All; 2; 5; 9; 10 | |
| http://mdc.itap.purdue.edu/item.asp?item_number=HO-223-W | Michael N. Dana and B. Rosie Lerner | Purdue Extension | All; 2; 5; 9; 10 | |
| http://mdc.itap.purdue.edu/item.asp?item_number=HO-224-W | Michael N. Dana and B. Rosie Lerner | Purdue Extension | All; 2; 5; 9; 10 | |
| http://mdc.itap.purdue.edu/item.asp?item_number=HO-225-W | Michael N. Dana and B. Rosie Lerner | Purdue Extension | All; 2; 5; 9; 10 | |
| http://mdc.itap.purdue.edu/item.asp?item_number=HO-226-W | Michael N. Dana and B. Rosie Lerner | Purdue Extension | All; 2; 5; 9; 10 | |
| http://mdc.itap.purdue.edu/item.asp?item_number=HO-227-W | Michael N. Dana and B. Rosie Lerner | Purdue Extension | All; 2; 5; 9; 10 | |
| http://extension.umn.edu/yardandgarden/ygbriefs/h408claysoil.html | Beth R. Jarvis | University of Minnesota Extension | All; 2 | |
| http://mdc.itap.purdue.edu/item.asp?item_number=HO-200-W | B. Rosie Lerner | Purdue Extension | All; 2; 7; 13 | |
| http://mdc.itap.purdue.edu/item.asp?item_number=bp-27-W | Paul C. Pecknold | Purdue Extension | All; 2; 16 | |
| http://www.hfrr.k-state.edu/DesktopModules/ViewDocument.aspx?DocumentID=1649 | | Kansas State Research and Extension | All; 2 | |
| http://www.extension.umn.edu/distribution/horticulture/DG2543.html | Carl J. Rosen | University of Minnesota Extension | All; 2 | |
| http://saylorplants.com/ | Jesse Saylor | Michigan State University | All; 3 | |
| http://www.taunton.com/finegardening/pguide/pronunciation-guide-to-botanical-latin.aspx | | Fine Gardening | All; 3 | |
| http://www.hort.uconn.edu/plants | Mark H. Brand | University of Connecticut | All; 3; 10 | |
| | Allen J. Coombes | Timber Press | All; 3 | |
| | A. W. Smith | Dover Publications | All; 3 | |
| | William Stearn | Timber Press | All; 3 | |
| http://plants.usda.gov | | USDA National Resources Conservation Service | All; 3 | |
| http://www.ars-grin.gov/cgi-bin/npgs/html/queries.pl | | USDA Agricultural Research Service National Germplasm Resources Laboratory | All; 3 | |
| http://www.efloras.org/flora_page.aspx?flora_id=1 | | Missouri Botanical Garden & Harvard University Herbaria | All; 3 | |
| | John P. Baumgardt | Timber Press | All; 3; 5 | |
| | James G. Harris and Melinda Woolf Harris | Spring Lake Publishing | All; 3; 5 | |
| | George W.D. Symonds | Harper | All; 3; 5 | |
| | George W.D. Symonds | Harper | All; 3; 5 | |
| | Benton M. Stidd and Robert D. Henry | Stipes Publishing | All; 3; 5 | |
| | Arthur Harmount Graves | Dover Publications | All; 3; 5 | |
| | Thomas S. Elias | Grolier | All; 3; 5; 10 | |
| order here | Sally Weeks and George Parker | Purdue Extension | All; 3; 5 | |
| | Sally Weeks, Harmon Weeks, and George Parker | Purdue University Press | All; 3; 5; 10 | |
| order here | Sally Weeks and George Parker | Purdue Extension | All; 3; 5 | |
| | William M. Harlow | Dover Publications | All; 3; 5 | |
| | Lawrence Newcomb | Little, Brown and Company | All; 3; 5 | |
| | Allan M. Armitage | Stipes Publishing | All; 3; 5; 9 | |
| | Doug Ladd | Falcon | All; 3; 5 | |
| | Richard H. Uva, Joseph C. Neal, and Joseph M. Di Tomaso | Comstock Publishing (Cornell University Press) | All; 3; 11; 20 | |
| view here, also available as book | North Central Regional Research Publication | University of Illinois Extension | All; 3; 11; 20 | |
| http://www.sldirectory.com/search.html | | Resources for School Librarians | All; 4 | |
| http://hanlib.sou.edu/searchtools | | Lenn and Dixie Hannon Library, Southern Oregon University | All; 4 | |
| http://searchenginez.com/tutorial.html | | SearchEngineZ | All; 4 | |
| http://ohioline.osu.edu | | Ohio State University Extension | All; 4; 21 | |
| http://urbanext.illinois.edu/hort | | University of Illinois Extension | All; 4; 21 | |
| http://www.uky.edu/Ag/HLA/homehort2.html | | University of Kentucky Extension | All; 4; 21 | |
| http://www.migarden.msu.edu/migarden/home | | Michigan State University Extension | All; 4; 21 | |
| http://www.uwex.edu/ces/wihort | | University of Wisconsin Extension | All; 4 | |
| http://www.yardandgarden.extension.iastate.edu | | Iowa State University Extension | All; 4; 21 | |
| http://mdc.itap.purdue.edu/item.asp?item_number=ID-414-W | Janna Beckerman and B. Rosie Lerner | Purdue Extension | All; 5; 9 | |
| http://hort.ifas.ufl.edu/woody/documents/EP310.pdf | Edward F. Gilman and Laura Sadowski | University of Florida Extension | All; 5; 10 | |
| http://orb.at.ufl.edu/TREES/index.html | | University of Florida, Rutgers University, and the U.S. Forest Service | All; 5; 10 | |
| click here for site assessment checklist and plant lists | | Cornell University Urban Horticulture Institute | All; 5; 10 | |
| http://plantfacts.osu.edu/Plant | | Ohio State University | All; 5; 9; 10 | |
| http://www.mobot.org/gardeninghelp/plantfinder | Kemper Center for Home Gardening | Missouri Botanic Garden | All; 5; 9; 10 | |
| http://www.bestplants.org | | Chicago Botanic Garden | All; 5; 10 | |
| http://woodyplants.nres.uiuc.edu | Gary J. Kling, Christopher P. Lindsey, Mark E. Zampardo, Laura L Hayden, and Christopher P. Lindsey | University of Illinois | All; 5; 10 | |
| click here - Selection Guide is located in upper left of page | | Morton Arboretum | All; 5 | |
| http://www.sustland.umn.edu/plant/plantdata.asp | | University of Minnesota Extension | All; 5 | |
| http://www.midwestlandscapeplants.org | William A. Hoch | University of Wisconsin Extension | All; 5; 10 | |
| | Connie L. Ellefson, Thomas L. Stephens, and Doug Welsh | MacMillan | All; 5; 7 | |
| http://www.marex.uga.edu/advisory/Library/CSCPpdfs/Xeriscape.pdf | Gary L. Wade, James T. Midcap, Kim D. Coder, Gil Landry, Anthony W. Tyson, and Neal Weatherly, Jr | University of Georgia Extension | All; 5; 7 | |
| http://www.vet.purdue.edu/toxic/cover1.htm | Rebecca J. Goetz, Thomas N. Jordan, John W. McCain, and Nancy Y. Su | Purdue Extension | All; 5 | |
| http://iuhealth.org/images/met-doc-upl/plant-guide.pdf | | Indiana Poison Center | All; 5 | |
| http://www.inpaws.org | | Indiana Native Plant and Wildflower Society (INPAWS) | All; 5 | |
| click here to find mail-order sources of plants | | University of Minnesota and Minnesota Landscape Arboretum | All; 5; 9; 10 | |
| | Marion T. Jackson, ed. | Indiana University Press | All; 5 | |
| | Kay Yatskievych | Indiana University Press | All; 5 | |
| | Gary Hightshoe | John Wiley and Sons | All; 2; 5; 10 | |
| | William Cullina | Houghton Mifflin | All; 5 | |
| | William Cullina | Houghton Mifflin | All; 5; 8; 10 | |
| | Carolyn Harstad | Indiana University Press | All; 5 | |
| | Samuel B. Jones, Jr. and Leonard E. Foote | Timber Press | All; 5 | |
| http://dnr.state.il.us/conservation/naturalheritage/prairie/table.htm | William E. McClain | Division of Natural Heritage, Illinois Department of Natural Resources | All; 5 | |
| http://www.btny.purdue.edu/weedscience/2005/weedlaw05.pdf | Glenn Nice | Purdue Extension Weed Science | All; 5; 20 | |
| http://mdc.itap.purdue.edu/item.asp?item_number=WS-30-W | Glenn Nice, Peggy Sellers, Bill Johnson, and Tom Bauman | Purdue Extension | All; 5 | |