Sources

• Rutgers NJAES, Landscape Plants Rated by Deer Resistance (E271)

  Every deer-resistance rating on the site. The four-tier scale and the plant list both come from here.

• NC State Extension Gardener Plant Toolbox

  Hardiness zones, cross-checked one record at a time. It corrected 115 of ours.

• USDA Plant Hardiness Zone Map

  The zone system itself, and the state ranges used to filter regional pages.

• USDA PLANTS Database

  Native range, state by state, for 198 records. Also the accepted botanical name where ours was a synonym, which is why some plants here are filed under a different name from the one on the label.

• Lady Bird Johnson Wildflower Center, Native Plant Database

  Growth habit, mature size, light and bloom season for the western native species. NC State does not cover most of them.

• El Paso County CSU Extension, Native Plant List for Deer Resistant Plants

  Deer resistance for 54 western species Rutgers does not list. It publishes a single category rather than a scale, so those records are mapped conservatively to the second tier and say so on the page.

• Penn State Extension, White-tailed Deer in Home Fruit Plantings

  The 8-foot woven-wire minimum for excluding deer from a larger area, and the fence-design detail behind the materials pages.

• VerCauteren, Van Deelen, Lavelle & Hall (2010), Assessment of Abilities of White-Tailed Deer to Jump Fences

  The fence-height table, and with it the eight-foot recommendation the whole fencing cluster rests on. Wild-caught deer jumping progressively taller fences: 0% deterred at 1.5 m, 14% at 1.8 m, 85% at 2.1 m, 100% at 2.4 m — which is 4.9, 5.9, 6.9 and 7.9 feet, and why those figures look so odd in imperial. Journal of Wildlife Management 74(6):1378–1381. A jumping-ability test on captive animals, so it measures what a deer can do rather than what one in your garden will.

• University of Minnesota Extension, Protecting Gardens from Deer

  The browse-reduction benchmark used across the deterrent pages — a 50% reduction is very successful and 30% is the likelier result — and the micro-exclosure finding behind every small-enclosure recommendation on the site: 8 by 16 feet at only 50 inches high has excluded deer.

• Oregon Department of Fish and Wildlife, deer and elk fencing guidance

  The ground-clearance figure. Deer go under gaps as small as six inches, which is why the fencing pages treat the ground line rather than the height as the usual failure.

• ASPCA Animal Poison Control, toxic and non-toxic plants

  Pet toxicity. A plant page says a plant is toxic only where the ASPCA lists it; saying nothing means it has not been checked, never that it is safe.

• Wikimedia Commons

  Photographs. Each is Creative Commons or public domain and credited to its photographer in the caption. All 526 are rehosted here rather than hotlinked.

• US Census Bureau, TIGER geographic data

  State boundaries for the map on the zones page. Public domain.

• State invasive species councils and departments of agriculture

  Invasive and prohibited listings. These change yearly, which is why plant pages tell you to check your own state rather than trusting the list here.

Plant descriptions are written for this site. They are not compiled from other gardening websites, which is why they sometimes disagree with the consensus you will find elsewhere. Where they do, the plant page says what the disagreement is.