Sunset system

This is a system used within the USA, particularly within western, frost free areas. It was developed by ‘Sunset’ magazine, hence the name. It incorporates summer high temperatures, lengths of growing seasons, humidity and rainfall patterns, as well as winter minimum temperatures. There are 24 zones within this system which, combined with the additional factors, make this a more precise system than the USDA zones.

Click here for details on the sunset system