Back to the Garden: High Altitude Orange Blossoms

Sheilah Britton

The image of plump, colorful fruit against a background of verdant green foliage leaves a lasting impression on any visitor to the Southwest who has left a white, snow-covered universe in the midst of winter. There is something slightly liberating about being able to pick fruit from a tree in your backyard, peel back its skin, and taste the complexity of its flavors in the middle of December.

Still, it is surprising that citrus seems to thrive in our communities. Glenn Wright, citrus specialist with the University of Arizona College of Agriculture and Life Sciences says it is the confluence of climate conditions that allows citrus to flourish at higher altitudes.

“SaddleBrooke at 3,200 feet appears to sit on a downward slope and is tucked next to the Catalina Mountains where cold air tends to move downhill, while SaddleBrooke Ranch, only 300 feet higher sits away from the mountains and at the top of a hill and is more exposed to frost and wind,” Glenn said.

The best time to plant citrus is late February to early May when the chance of frost has passed, and September to November between the heat of summer and early winter. Kumquats and Satsuma mandarins are cold hardy, as are tangerines, tangelos, navel oranges, and grapefruit to around 20 degrees Fahrenheit. Covering trees with frost cloth when temperatures dip into the mid-thirties will help to retain the heat of the day, as will keeping the soil around the tree moist. A sunny location with southern exposure is best and if you live in SaddleBrooke Ranch, you should also plant in an area that is protected from wind.

Once you’ve chosen citrus and located a good spot to plant, your next concern will be a steady, reliable source of irrigation for your trees. The variety of tree, age, size, and season will inform the best water applications. Generally, trees should be irrigated every seven to 28 days, based on the season, soil, and drainage. You will find detailed charts and tables on the following document: ag.arizona.edu/pubs/crops/az1151.pdf.

While there are as many criteria for fertilizing citrus as there are for irrigation, a good way to remember when to fertilize is to mark your calendar for Valentine’s Day, Memorial Day, and Labor Day. Nitrogen (N) is the most important nutrient for citrus growth, followed by Phosphorus (P), Potassium (K), and trace minerals. There are many compounds of fertilizer available including some specifically for citrus.

Your citrus will not need a lot of pruning once it is established. Light pruning for suckers and frost damaged branches should happen in early March after the threat of frost has passed. When necessary, remove undesirable or dead wood, crossing branches, and thin to allow light in if fruit production is low.

While Arizona’s citrus industry has declined significantly in the past few decades, Glenn Wright believes there will always be growers in the Southwest.

“We probably will never get back to 70,000 acres of citrus that Arizona had in the mid-1960s. Urbanization changed all that. But as long as there are consumers, Arizona is still a great place to produce citrus,” he said.

Especially if you can do it in your own backyard.

If you have questions about your plants, irrigation, or landscaping contact SB/SBR Master Gardeners at [email protected] The service is free.

SaddleBrooke/SaddleBrooke Ranch Master Gardeners are volunteers trained under the auspices of the University of Arizona, Cooperative Extension, Pinal County. We offer educational programs and classes to residents of our communities. Please visit our new website at www.extension.arizona.edu/saddlebrooke-master-gardeners.