Government agencies, universities and research centres
NC State Extension Gardener Plant Toolbox
Size, form, light, soil, hardiness and care, and its "invasive or weedy" tag.
Cited 39,626 times on 1,859 plant records.
USDA PLANTS Database
Names, native status, growth form and habit, and the symbol that links each plant to its profile.
Cited 28,954 times on 6,781 plant records.
Lady Bird Johnson Wildflower Center Native Plant Database
Light, moisture, bloom time, native range, deer resistance and larval hosts.
Cited 14,797 times on 2,559 plant records.
EPA Level III Ecoregions of the continental US with state boundaries (shapefile)
Which ecoregion a garden's town falls in, so the right regional plants load.
Cited 2,399 times on 2,399 plant records.
Plants of the World Online (Royal Botanic Gardens, Kew)
Accepted names, family and native distribution.
Cited 1,104 times on 210 plant records.
Catálogo de las plantas vasculares de Chile (Universidad de Concepción)
For the Chilean gardens: accepted names, family, whether a plant is native, endemic or introduced, and where in Chile it grows.
Cited 1,066 times on 109 plant records.
Mt. Cuba Center
Deer resistance, native range, pollinator value and site notes for Mid-Atlantic natives, from its plant profiles and trial-garden evaluations.
Cited 420 times on 160 plant records.
Cited by hand from the institution's publications; we are checking each citation against its source.
Cornell Cooperative Extension
Deer resistance and site guidance for New York gardens.
Cited 233 times on 232 plant records.
Cited by hand from the institution's publications; we are checking each citation against its source.
GBIF — Global Biodiversity Information Facility, occurrence API
For the Chilean gardens: where each species has been recorded, used to choose the native plants of each ecosystem.
Cited 115 times on 109 plant records.
Pisos vegetacionales de Luebert & Pliscoff (Ministerio del Medio Ambiente, Chile)
For the Chilean gardens: the vegetation zone each plant belongs to, which sets the gardens' beds.
Cited 109 times on 109 plant records.
Xerces Society regional pollinator plant lists
Pollinator and larval-host flags. Every value credited to Xerces was checked against xerces.org on 1 November 2026; what Xerces does not state was re-sourced or removed.
Cited 37 times on 31 plant records.
UMass Amherst Extension
New England horticulture.
Cited 24 times on 24 plant records.
Cited by hand from the institution's publications; we are checking each citation against its source.
Rutgers Cooperative Extension
Deer-resistance ratings, from its bulletin Landscape Plants Rated by Deer Resistance.
Cited 15 times on 15 plant records.
Cited by hand from the institution's publications; we are checking each citation against its source.
Cornell Lab of Ornithology
Which birds use a plant.
Cited 11 times on 11 plant records.
Cited by hand from the institution's publications; we are checking each citation against its source.
University of Connecticut Extension
New England horticulture and native plants.
Cited 3 times on 3 plant records.
Cited by hand from the institution's publications; we are checking each citation against its source.
National Wildlife Federation — Keystone Native Plants by ecoregion
The keystone genera of each ecoregion; the Keystone badge is worked out from these lists.
Used by the app itself; no record cites it field by field.
Botanic gardens and plant societies
The published plant lists of 0 botanical and public gardens
Which plants a garden grows, from that garden's own published plant list, cited by the garden's own name.
Cited 4,054 times on 2,503 plant records.
Calscape (California Native Plant Society)
Light, water, bloom, size and wildlife value for California natives, credited on each value as its terms require.
Cited 2,169 times on 200 plant records.
Chileflora.com — Database and Interactive Encyclopedia of the Chilean Plants (M. Belov)
For the Chilean gardens: hardiness, sun, water, size, flower colour and propagation.
Cited 675 times on 85 plant records.
iNaturalist — research-grade observations with the 'Flowering' phenology annotation (API)
For the Chilean gardens: the months a plant flowers, from research-grade observations marked as flowering.
Cited 86 times on 63 plant records.
Missouri Botanical Garden Plant Finder
Native range, seed treatment, hardiness and wildlife value.
Cited 63 times on 58 plant records.
Cited by hand from the institution's publications; we are checking each citation against its source.
General references
Wikipedia (English), article lead
The opening description of a plant, where no source above has one.
Cited 831 times on 813 plant records.
Stonecrop Gardens, Garden Tour handout (Cold Spring, NY), 2022-08-26
Which plants grow at Stonecrop Gardens, from its garden tour handout.
Cited 9 times on 9 plant records.
What a citation tells you. In the app, open any plant: the Sources line under its name opens the list of sources behind its fields, each linked to the source's own page for that plant where one exists. A field no source states is left empty, never guessed.
The rules each record is held to are on Our editorial standards; who builds and checks the records is on How we work. To report a wrong fact, write to hernan@gardeninglab.eco; a person reads every correction.