Plant Hardiness Zone Maps Around The World

The Plant Hardiness Zone Map And How To Use It In Edible Landscaping

Plant hardiness zones are areas of the world that have the same minimal annual temperature. The plant hardiness zone assignment (for example, on a tag or label) tries to tell you how much cold a plant can withstand.

Hardiness zone maps are extensively used by websites, books, magazines, and other publications to give you some idea of whether a plant can survive the winter in your area. In general, when you're looking for plants to buy online, you'll be asked for your hardiness zone.

How to find your plant hardiness zone

To find your plant hardiness zone, you need a plant hardiness zone map for your area.

Plant hardiness zone maps began with the USDA plant hardiness zone map (the link includes Puerto Rico), developed by the US Department of Agriculture. Many other countries use it as well.

PlantMaps is a great resource, with plant hardiness maps for many countries and regions of the world.

There are some drawbacks to simply mapping the USDA map onto another country (one being the differences in climate caused by the ocean on an island country like the UK, for example), so the Royal Horticultural Society and the EGF have developed their own maps and zoning systems.

Click to get a free fact sheet I've made for you on how to translate USDA numbering to the Canadian, RHS, and EGF systems, and vice versa. 

(a new page will open and you can close that page to return here)


Here are some hardiness maps for regions which the above two links don't cover. Although many of them are just the USDA temperature classifications mapped onto other countries, some countries have developed their own maps, and if you live in one of these countries, you should study how the numbering systems differ.

Many of these maps are pdf files, which you will need the free Adobe reader to open on your computer. If you don't have this, you can download it by clicking here. (a new page will open and you can close that page to return here)

Basically the USDA map put onto the African continent.

A USDA hardiness map put onto southern Africa.

A PDF file of the South American USDA zones. I find this difficult to read because the zones are not color-coded, just written on the map, but this show topography, cities, and includes zones 12 and 13 which are not seen in North America, so it may be quite useful for you.

Problems with plant hardiness zone maps

Plant hardiness zone maps have several drawbacks, the first being how the maps are constructed.

In the US, the maps are a recording of the average lowest temperature over a period of many years. If you live right at the border to the next lower zone, have plants that can just barely tolerate your zone, and have a unusually cold winter, your plants may not survive without protection. 

So you can't take the map at face value.

The other problem is that the map doesn't take into account the effects of snow cover. Snow insulates plants, acting just like a blanket. If you live in an area that is under snow all winter, your plants will do much better than those areas with no snow even if you live in the same zone, especially if you have high winds. The lower your zone number, the more this wind damage has to be accounted for. 

In any zone, you have to watch your plants carefully if you live in an area that is very windy during the winter, because the wind can dry your plants out and kill them even in a zone they should be able to survive.


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