Credits

Where Loamhand's location, weather, climate and plant data comes from.

Place search

Searching for a location, and finding the postcode a hardiness zone is looked up from, uses OpenStreetMap contributors' Nominatim service, under the Open Database Licence (ODbL).

Hardiness zones

PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed 2026-09-21: PRISM's listing of zones by ZIP code for the 2023 USDA Plant Hardiness Zone Map, which remains the property of Oregon State University. What a garden shows is looked up from that data by its ZIP code; it is not the official USDA Plant Hardiness Zone Map.

Forecasts

In the US, forecasts are from the National Weather Service (NOAA). Outside the US, forecasts are from MET Norway, under CC BY 4.0.

Frost dates

Frost dates are from NOAA's 1991–2020 U.S. Climate Normals: Palecki, M., et al. (2021), U.S. Climate Normals 1991-2020, Annual/Seasonal, NOAA National Centers for Environmental Information, doi:10.25921/4ek7-fk11.

Elevation

Ground elevation, used to choose the weather station a garden's frost dates come from, is from the USGS 3D Elevation Program (3DEP) via its Elevation Point Query Service.

Plant photographs

Plant photographs are from Wikimedia Commons. Each one is credited to its photographer and licence on the plant's own page.

Plant facts

What a plant's page says about it — spacing, watering, days to harvest, safety and the rest — is cited on that plant's own page, source by source.