How the list was made
We started from two open sources: Wikidata (public domain), which lists botanical gardens and arboretums in the United States, and OpenStreetMap, used only to find candidates and their websites. After removing records with no name, closed places, private areas and duplicate map objects, 1,357 candidates remained. Collections inside a larger garden were kept with that garden, not listed separately.
How each garden was checked
For every candidate with a website we saved its official homepage and visitor, hours and admission pages. A garden is listed only when that official text shows that the public can visit and gives at least one visit fact beyond the address. Every published fact is tied to a quotation from the saved official text; facts we could not tie to the text are left as “not recorded”. 523 gardens passed. Places we could not check are not listed; that does not mean they are closed.
What the data does not prove
This is not every garden in the country. Many small gardens have no official website we could read, and some websites refused automated or browser access. States with no listed garden may still have public gardens.
What a check date means
It records when a source was reviewed, in U.S. Pacific time (our saved source files record the same moment in UTC, which was already the next day). It does not promise that admission or hours are unchanged. Seasonal date limits and visitor notices matter. When a schedule we recorded has ended, the garden page says so and points to the official source.
How “free” is used
Free means the official source says regular garden entry is free. Parking, events and special programs may still be charged. Conditional free days at normally paid gardens do not qualify.
Locations and distances
Street addresses come from the gardens’ own websites. Map positions come from the U.S. Census Bureau geocoder applied to those addresses; where the geocoder found no exact match, we use the garden’s own map point from OpenStreetMap or Wikidata, checked against the garden’s ZIP code. City and ZIP search uses Census place and ZIP code reference points. Distances are straight-line miles, not driving distances.
Missing or incorrect information
Email [email protected] with the page address and a link to the official source. Changes are checked against the garden’s own website before anything is updated.
Independent advertising
Advertisements are labeled and separate from the garden list. Advertisers do not affect the order of results or the admission filter. We have not asserted an affiliation with any listed garden.