Planting Zones USA and Canada
The maps below show the planting zones – also known as plant hardiness zones or growing zones – for the USA, Canada and Europe.
USA Hardiness Zones
There are 11 planting zones in the US and southern Canada. These areas are defined by a 10 degree Fahrenheit difference in the average annual minimum temperature.
Simply put, a higher zone number means warmer temperatures.
Zone 1 is the coldest with zone 11 being the warmest – a tropical area found only in Hawaii, coastal Southern California and southernmost Florida.
Basically, plant growing zones are a guide to help you know which plants will grow where you live
You will see seed packets and seedling plants labeled according to the plant hardiness zone that they will grow best in.
The map gives a broad idea of the planting zones for the US, but for a more detailed guide consult the USDA Map
The growing zones themselves are just a rough guide. And there are large variations in climate between places in the same zone. For example although both Austin, Texas and Portland, Oregon are in the same zone (8), the local climates are dramatically different.
The average minimum temperature is not the only factor in figuring out whether a plant will survive in your garden. The map is a useful guide, but it is only one small part of the picture. You still need to consider other factors which all have an effect on your plants growth.
- Growing Season – This is the period of frost free days so knowing your first and last frost dates is important. Also bear in mind that if you live high on a hill, or deep in a valley, your frost dates may be different than your fellow gardeners in other parts of your area.
- Soil type
- Day length
- Daytime temperatures