Here’s a complicated question for you. What exactly is a native plant? How do you determine what is “native” to your area? Is it a plant that is found in your community? In your ecological area? In your state? How about the state next door? Let’s break this down with some examples.
The Sonoran Desert encompasses areas in California, Arizona, and the Mexican states of Sonora and Baja California (see map below). Since I live in the Sonoran Desert, one could argue that any plant from any of these states is a native plant. But the Sonoran Desert only takes up a tiny part of California, so it doesn’t make much sense for me to plant other California plants (like ones from coastal areas).
In this case, I would choose plants that are native to the ecosystems of the Sonoran desert. You could get even more granular than this—are you thinking of plants from the low desert or high desert? Canyons or foothills? The northern regions or the southern? The variety of topography, latitude, and altitude means that there’s huge variation in what plants grow and thrive even in different regions of the Sonoran Desert.
Let’s also look at the Mojave or Chihuahuan Deserts next door. Many of the native plants there overlap. This is to be expected—it’s humans who like to draw neat clean lines between regions, but Mother Nature doesn’t look at maps. The deserts which humans have partitioned up actually blend into each other. This means that some plants native to the Chihuahuan Desert or the Mojave would actually do very well here in the Sonoran. Some people like to refer to these plants as “near-natives”.
How precise you want to be partly depends on the purpose of your garden. Are you trying to provide a unique habitat for wildlife that is becoming hard to find? Are you trying to cultivate rare native plants for seeds? Are you trying to recreate a certain mood or setting in a part of the Sonoran Desert that you love?
It also depends on your location. If you’re close to the “border” with another desert or ecosystem, you can definitely use plants from that area, as they will likely do well. If you’re at a higher elevation, note that some Chihuahuan Desert plants have higher cold tolerances and thus may do better than strictly “native” Sonoran Desert plants.
For all of these reasons, it pays (in my opinion) to be a bit flexible about your definition of native. I tend to stay away, however, from desert plants from other continents (Asia, Australia, South America or Africa). This is due to the possibility of these plants becoming invasive and pushing out our unique natives. That’s not to say that I am against using them completely; it may be fine to plant them in containers or in very urbanized areas. However, I avoid planting them in wilder desert areas and particularly near washes, since the extra water availability in canyons and wetter areas can allow invasives to take hold.
