How we source & fact-check our plant data

Our data sources

• Pet toxicity — the ASPCA Toxic and Non-Toxic Plants database, cross-checked against the Pet Poison Helpline, NC State Extension and the Merck Veterinary Manual where a species is not individually listed.
• Cold hardiness — the USDA Plant Hardiness Zone Map (1991–2020 normals) and the RHS hardiness rating system.
• Care (light, water, soil, humidity) — US university Extension services (Missouri, Illinois, Penn State, UF/IFAS, NC State and others) and the Royal Horticultural Society, supplemented by established horticultural references.
• Our catalogue — 8,452 structured species records compiled and maintained by the Growli editorial team, the basis for our open data studies.

How we fact-check

Evergreen botanical facts (the light and water preferences of well-known houseplants, basic plant biology) can rely on established horticultural knowledge. But every specific claim — a cultivar name, a statistic, a study citation, a regulatory fact, a toxicity verdict, a UK-localised detail — is verified against an authoritative source (a .gov, .edu, the RHS, ASPCA or USDA) before it ships. If a number cannot be confirmed, we soften the language (“typically”, “in many regions”) rather than invent a figure.

The pet-safety gate

Toxicity is the claim we treat most strictly, because a wrong “pet-safe” label can put an animal at risk. Our classifications are grounded in the ASPCA database. Where the ASPCA lists a genus by name (for example “Begonia spp.”), we apply that verdict across the species in our catalogue belonging to that genus — consistent with how the ASPCA itself frames genus-wide toxicity. Where only a representative species is listed, we extend the verdict across the genus only when the shared plant chemistry is corroborated by Extension or veterinary sources. A species is never marked pet-safe on assumption: every record passes an automated genus-level safety gate that forces a toxic classification for any plant family with a known toxic principle, and our “mildly toxic” tier flags species likely to cause mild gastrointestinal upset rather than systemic harm. Always confirm an individual plant at aspca.org or with a veterinarian before assuming it is safe.

Corrections & updates

Plant taxonomy and toxicity guidance change. We revise records as sources update, and we welcome corrections — if you spot something that conflicts with an authoritative source, tell us via the contact page. Care guides are written by the Growli editorial team; we never attribute content to a fictitious single author.