Data sources
Seeds Galore is built on public and open datasets. A seed packet's own values always take priority over anything below — this is reference data, not a substitute for what's printed on your packet.
USDA Plant Hardiness Zone Map (2023)
U.S. Government work — public domainHardiness zone lookup by ZIP code
Served via phzmapi.org, a community project — its own terms of use aren't formally confirmed, so a self-hosted ZIP→zone table is used as a fallback if it's unreachable.
NOAA / NCEI 1991–2020 U.S. Climate Normals (Agricultural Normals)
U.S. Government work — public domainLast-spring and first-fall frost dates by weather station
OpenFarm growing-guide data
CC0 1.0 Universal (public domain dedication)Sun, spacing, and sowing-method defaults for 340+ crops
OpenFarm.cc shut down in 2025 without releasing an official data dump. This app uses a community rescue of the archived site (thefullnacho/openfarm-crops-rescue), independently spot-checked against the live Wayback Machine captures it cites before import.
USDA PLANTS Database, via GBIF
CC0 1.0 Universal (public domain dedication)Canonical plant/species names, synonyms, and taxonomy lookup
Hand-curated reference data
First-party, sourced from extension-service guides and seed-company grower referencesA small set of common crops (days to maturity, spacing, planting timing) and the offline fallback hardiness-zone/frost tables
Full sourcing notes and verification methods are documented in docs/research/ in the project repository.