Tuesday, January 17, 2012

Plant Hardiness Zones Maps for the World

World Plant Hardiness Zones Map

In a previous article I discussed the U.S. Hardiness Zones (you can read that article here). I use these zones in each of my plant articles. I recently received an email from a reader telling me that the Zones I discuss mean nothing to them as they are in Greece. While I use zones that are tailored to the U.S., there are similar zones outlined for all parts of the world. Many of these zones use the same temperature scales, and others do not, but it is not too hard to go from one to another if you have both map keys available.

In brief, a Hardiness Zone Map divides an area into Zones (typically 1 through 10 based on minimum temperatures, with 1 being the coldest and 10 being the warmest).  A plant is placed into one of these Hardiness Zones based upon the lowest temperature it can withstand.  As I have stated previously, the benefit of Hardiness Zones is that it provides a starting point for planning which plants can winter-over where you live.  However, there are a few drawbacks to the Hardiness Zone Map.  It does not consider day length (which changes considerably the further from the equator you go), snow cover (which moderates soil freezing and insulates roots), humidity, frost, or soil moisture.  Probably the biggest drawback is that it does not consider how warm your summer will be.  The classic example is comparing the Shetland Islands north of Scotland and southern Alabama.  Both are listed as bewteen Hardiness Zone 8-9.  However, the Shetland Islands are sub-artic and southern Alabama is sub-tropical.  There are almost no plants that can grow in both places.

I hope this helps anyone struggling to determine in which Plant Hardiness Zone you reside.  Here are the links to pages that have the best Plant Hardiness Zones maps I can find for locations around the world:
  1. Africa - Not a very detailed map at all, but the only one I could find for the entire continent.  There is a much more detaile map of Southern Africa here. 
  2. Australia - Not extremely detailed, but still very useful.  Also, it has a comparison to the U.S. which can be quite helpful. 
  3. Canada - Very detailed map, but may be a little hard to use as the zones blend into one another... but I guess that is how things actually are in real life. 
  4. China - Pretty good map.  There may be better ones out there, but they are not available (or searchable) in English, and my Mandarin is not good at all. :)
  5. Europe - Pretty good map.  There is a list to specific countries that link to a larger (close-up) map.
  6. India - No specific map found.  The only map that I could find is at the top of this post.
  7. Japan - Fantastic interactive map.
  8. Russia - Map is fair, but the information is good.  Includes areas/countries that belonged to the former USSR.
  9. South America - Not super detailed and maybe a little hard to see the zone deliniations, but still reliable.
  10. Southeast Asia - No specific map found. The only map that I could find is at the top of this post.
  11. United States of America - link to my previous article.


7 comments:

  1. Awesome! I've been looking everywhere for a decent zone map so I can look at plant's native habitats and know where they like to live. Thanks a lot!

    ReplyDelete
  2. Fantastic, thank you!!

    ReplyDelete
  3. Thanks. It would be great to get a higher resolution of the map if possible.

    ReplyDelete
  4. Is there a list of which plants do well in which zone, so I know which ones to plant in zone 12?
    Monica
    (Please send answer to guayabapr at gmail dot com if possible)

    ReplyDelete
  5. Link to Europe map no longer works

    ReplyDelete
  6. Thank you for putting this together! Very helpful. Bev

    ReplyDelete