Grow a Garden in Arizona's Low Desert Climate

By Hy Rillero

Published on June 2, 2020

Growing a viable garden in Arizona is a unique challenge. Arizona is an extremely diverse state. It's home to all four of the different types of North American desert biomes (Source 1). Many parts of Arizona will reach extreme levels of heat with very low humidity. In fact, in terms of average annual precipitation, Arizona ranks 49 in the United States (Source 2). It doesn't seem like an encouraging statistic for the beginning gardener; however, with the proper knowledge and tools, many types of gardens can grow and thrive in Arizona.

The placement of the garden is one of the most important factors a beginning gardener will control. The ideal amount of sunlight varies from plant to plant. However, with harsh temperatures peaking around mid to late afternoon, it is perfect to have plants in a location that will favor sunlight in the morning and restrict it in the afternoon. Sunlight from the East will come during the cool morning, and sunlight from the West will scorch your garden dry if not prevented. If your location prevents you from having an ideal garden space, you may consider taking a look into what types of plants would be better suited to the harsher amount of heat they will receive. Another solution might be to artificially block the crops from the Westside sunlight if this is a problem that presents itself. A simple tarp or tapestry could do the trick. One common solution to the problem (that is arguably more visually pleasing) is planting a larger, native Arizonan plant on the West side of your garden to block the harmful sunlight from your more fragile plants. Some plants that grow well in Arizona soil include the Palo Verde tree or one of the many different shrubs that thrive here.

It's important to be aware of the proper time to begin planting a specific crop type in any location. Many plants can thrive in Arizona if planted at precisely the right time; they are very likely to fail. For instance, from August to December, it is the best time to plant kale, whereas March to May is great for planting okras. Click here for an extensive list of plant and harvest timelines as well as general advice for planting specific crops in Arizona (Source 3). Often, seed packages will display the USDA Plant Hardiness Zone Map. The map shows the average annual extreme minimum temperature for specific areas. You can find this image on the USDA site. Depending on where you live, your zone will change. Most of the valley of Arizona is from zones 8b to 9b. Different zones will mean starting plants on their life cycles at different times. A standard plant chart shows the month when you should begin to the plants, often as seedlings indoors. It details further when the plant should be moved outdoors and then finally harvested. Once you have determined your zone, you may use a search engine to find a plant chart for the type of garden you plan. For example, if you were in zone 9 looking to start a vegetable garden, you may search "Zone 9 vegetable planting calendar/schedule." This information should bring up a plethora of reliable sources to use.

Choosing and maintaining soil is critical to the life of a healthy vegetable garden. Ideally, your soil will contain a mixture of soil compost, peat moss, and perlite. Peat moss aids greatly in water retention of the soil because of its properties of absorption. Perlite increases air space in the soil to aid in water drainage.

If you are planting from the ground or container, such as a pot, your soil will vary. At your local home and garden store, you should be able to find labeled pot soil and garden soil. For vegetables to thrive,  the soil pH is determined based on the plant's need. Because of the Arizona climate, the soil pH should range between 6.0 to 7.0. The increased bioavailability of different nutrients between these ranges helps vegetables to grow. A soil test kit can be available at most home & garden stores to determine the pH of your soil mixture. If you want to raise your soil's pH level, you can use lime or wood ash. Sulfur, peat moss, and compost will lower your soil's pH level.

Growing any garden is a difficult task. This state provides some difficult challenges for even the master gardener. Harsh summers, dry air, and extreme heat seem like a recipe for a disaster of garden-ic proportions. Despite this, time and time again, UFE has helped local businesses, communities, and families begin thriving, productive gardens right here in the valley. With the information above, you are well on your way to your first harvest in Arizona.