A parser for USDA plant hardiness zones. It uses the ZIP-querying API built into the U.S. Department of Agriculture’s Plant Hardiness Zone website (e.g., http://planthardiness.ars.usda.gov/PHZMWeb/ZipProxy.ashx?ZipCode=55555) to retrieve the plant hardiness zone data for every ZIP code, one by one. Rate-limited to 1 query per second, this takes a little over 8 hours to run.
./frostline.py -z zipcodes.csv
You can generate a nice interactive map of the data. First convert the data to GeoJSON:
node map.js
This creates map.geojson. Then view map.html in a browser. You will need to serve the map on a simple web server (not at a file:// URL) so that it can access the GeoJSON file on disk (file:// URLs block access to other files). That was used by Josh Tauberer to generate the above map.
This is the national standard for knowing which plants will grow where. It’s determined based on the average annual minimum temperature over the prior 30 years, with each zone comprising a 10°F band. There are 26 zones in all. The standard was developed by the U.S., but other countries have adopted the same standard. Companies that sell plants, seeds, roots, and bulbs (e.g., Burpee) use these zones to help customers understand what will thrive in their area, and to decide when to ship orders to help them to thrive. For more information, see the Wikipedia entry or the USDA’s explanation.