In the gardening world, Phoenix is usually referred to as low or subtropical desert. Under 5,000 feet in elevation, we are located in the Sonoran desert.
This means it is very hot and dry in the summer and cooler but still dry in the winter. Rainfall that we receive usually happens in short bursts in the winter and during the monsoon season.
As you can see from the USDA Plant Hardiness Map there can be multiple gardening zones within one state. About half of the state of Arizona falls into the 9a to 9b zone, however the other half ranges from 6a to 7a with a few areas as cold as gardening zone 4b.
Phoenix Gardening Zone
There are three main gardening zone maps including:
Phoenix, Arizona is in the following gardening zone: USDA gardening zone 9b, Sunset Zone 13, and in Plant Heat Zone 11.
How is the Gardening Zone determined?
No matter where you live in the U.S. it is helpful to know your gardening zone. Why?
This information tells you how a plant will survive during the winter months, how well it will manage heat in your gardening zone and how well it will thrive in your particular zone.
With this knowledge you can choose plant varieties that will have a greater chance of success in it’s environment.
USDA Chart – Will the plant survive winter in this zone?
USDA charts are used to determine how cold of temperatures a plant can survive. It looks at winter temperatures in the area and determines if the plant will survive winter.
Sunset Climate – Will the plant thrive year round in the zone?
The Sunset climate zone chart takes into account the geographical location, elevation, start & end frost dates, and humidity levels. It considers where the plant will thrive year round. For this reason, the Sunset Climate map is a more thorough reference for growing in the desert.
Plant heat zone – Will THis Plant survive the heat in the zone?
Another gardening zone map is the Plant Heat Zone map from the American Horticultural Society. This chart uses the National Weather Service’s average number of days with a temperature over 86 degrees to determine the plant heat zone. Phoenix is in heat zone 11.
What do the Gardening Zones Mean?
Plants have a maximum hardiness zone, a minimum hardiness zone, a maximum heat zone and a minimum heat zone.
Phoenix is in Sunset gardening zone 13, which offers gardeners an opportunity to grow many plants year round.
However, for the best results it is important to plant your vegetables and flowers the right time of year.
When choosing plants you want to make sure that they will be able to grow where you live and if it will produce vegetables or fruit. Nothing is more disheartening than watching your beautiful plant wither from the heat.
Sometimes plants tagged as annual will continue to flower for several seasons if taken care of. For example, tomato plants are annual plants, however with the right care they can last many years.
Now that you know what gardening zone Phoenix is in let’s get our hands dirty and grow something