Zone Maps, Worldwide by Continent

The purpose of this and further posts in this area is to give members an idea of their growing zones. These are general guidelines only, as there are places on this map that I know are a different season by one week of growing days in either direction within my zone. *My zone is 3a according to this map, but a more detailed map puts me in zone 3b along with an area that I know still has a week longer season than we have here. I suspect that they are actually a 4a.*

There are also microclimates within each general zone which can boost that particular area in your region, or even your yard or particular places in your yard, by a zone or more. Many factors come into play to establish a microclimate...but it is often a very happy discovery!

*If you have found a fantastic zone map of any other continent, please pm me with the web address and I will add it below.*

We will start with a zone map of North America. I will add more over time as I discover more to share with you all.

Comments

  • LaurieLovesLearning
    LaurieLovesLearning Posts: 7,356 admin
    edited October 2020

    North America


  • LaurieLovesLearning
    LaurieLovesLearning Posts: 7,356 admin
    edited October 2020

    The link contains a general map list of many continental hardiness zones. It may take some time to load once clicked on. Please be patient.

    *I am still welcoming link suggestions for maps that you have found useful for your continent (other than North America). Please PM me if you have any suggestions for me to consider adding. Thank you.*

  • LaurieLovesLearning
    LaurieLovesLearning Posts: 7,356 admin

    I found a map for the US that you can search by postal code. Of course, growing zones aren't perfect. This is to give a starting point. I also think it's kind of fun figuring out what the site might claim.


  • JennyT Upstate South Carolina
    JennyT Upstate South Carolina Posts: 1,273 ✭✭✭✭✭

    Ahh yes, this is better. Thanks, @LaurieLovesLearning. I tried looking at a map from the other link and it didn't have all of the state lines for SC on it. So I had no point of reference. 🙃

  • annbeck62
    annbeck62 Posts: 994 ✭✭✭✭

    This is interesting. I entered my zip code and my zone has changed from 9b to 10a. Although our winters are so unpredictable here, I'm not sure I'll rush to buy plants zoned for 10a. This year, we could of had a white Christmas, brrrr.

  • Torey
    Torey Posts: 5,502 admin

    The last time a new map came out, my zone had changed from 3b to 4a, although in my area, with such a great change in elevations it is difficult to pinpoint each location within a zone. About 3 km as the crow flies, from my house, there is a micro climate along the river (1300 feet elevation) that is rated as high as zone 6. I'm at 2600 feet. However, if you go up the hill (mountain) behind my house by only 1 km (3700 feet elevation) you will be in zone 2 habitat.

    As Laurie has pointed out, even within your own property, you might have the difference of a whole zone. Wind breaks make a difference. Rock walls around sun pits make a huge difference. My daughter lives about 1/2 km down the road and sometimes one of us will get a frost but the other is a couple of degrees warmer with no frost.

    So I try and push the boundaries, trying plants that are zone 4b or even 5. Sometimes I will get lucky and other times not. Its exciting when you get something to survive that isn't supposed to grow in your area. I have a purple smoke bush which is a zone 6 plant. It only flowers and gets "smoke" on old wood so I don't always get the "smoke" as it dies back to the ground in some years. Probably this year as there wasn't much snow cover when we had that really cold spell. I have seen others growing in zone 6 gardens and they become almost tree form with an older established trunk but mine will never be anything more than a shrub. But exciting on those years when it does do well.

  • VermontCathy
    VermontCathy Posts: 1,911 ✭✭✭✭✭

    There is a certain amount of fuzziness in all zone boundaries. I wouldn't be concerned about a half-zone shift, from 4a to 4b, or 4b to 5a. Local microclime effects can easily cause that much shift, if not more.

    If you are very close to the edge of the zone where the crop you are considering is widely grown, be cautious. Weather has been more unstable in the 21st century than in the 20th. The 19th century was also unstable, so the 20th was probably the unusual one.

    Also, zones are defined by winter temperatures, so they are very meaningful for perennials, but less so for annuals. Even among perennials, you need to understand what is causing the limit. If you are risking the survivial of a tree in the cold, that could be an expensive and time-consuming gamble, but if you are only risking one year's fruit from the tree if conditions are cold, that's much less of a risk.

    For determining what annuals you can grow, looking at the maximum and minimum temperatures that a crop can tolerate and the days between your last and first frost will be a much better predictor than the zone number.

  • Cornelius
    Cornelius Posts: 872 ✭✭✭✭

    It says that I am a zone 7a. I will definitely be experimenting more this year to see what I can grow and increase yields!