Some of my earliest memories are of trees in our front yard. In the spring, the sweet olive burst with blossoms, cascading underneath the canopy, their white petals the closest thing we had to snow in Louisiana. Southern live oaks dripping with Spanish moss created archways for roads. My dad’s backyard lemon tree produces such abundance that he fills his wheelbarrow with bagfuls, posts a sign, and arrives home to find it empty.
When I moved to the desert almost a decade ago, I didn’t notice the trees at all. I noticed saguaro and cholla and prickly pear and agave and creosote. I noticed the zigzagged slopes of the Catalinas rising violet against the sky. I fell in love with the landscape, but to me, that landscape was not about trees. In Louisiana, trees grow gigantic, impossible to ignore; you put a tree in the ground and it grows. In the desert, what appears to be a stick or shrub could be a burgeoning tree. In the desert, care is required for trees to take root and thrive. But the desert also teaches you—if you are willing to learn—that it is bountiful in ways that, on first glance, you could not have imagined.
“I think most people don’t think about trees when they think of the desert, maybe even those of us that live here,” says Ann Audrey, steering committee chair and project manager for the Linking Edible Arizona Forests Network, or LEAF.
The LEAF Network is a community-based organization focused on teaching Arizonans about trees. Partners include the Arizona Community Tree Council, Pima County and Phoenix Parks and Recreation, Trees for Tucson, Tucson Oasis Initiative, Iskashitaa Refugee Network, American Rainwater Catchment Systems Association, GRS Landscape Architects, Sustainable Cities Network, and the University of Arizona Cooperative Extension.
Audrey wonders: “What will it take for people to think of trees as being a vital part of the landscape?”
Part of that shift means awareness and education and LEAF is at the forefront of this work, working to connect trees with people who can serve as stewards and educate people about the benefits of edible trees. And there are many.
Trees provide shade and cool the air around them through the process of transpiration. Many trees convert nitrogen from the air into fertilizer for the soil. They help reduce the urban heat island effect and add beauty to urban landscape. And, of course, edible trees provide local food that people can use to sustain themselves and their families.
A decade ago, Jesús Garcia, director of the Kino Heritage Fruit Trees Project, began traveling the Southwest to collect cuttings from descendants of trees brought by European missionaries, including Father Kino, in the 1600s. He applied his academic interests and horticulture experience from growing up in orchards in Mexico to the cultivation and propagation of these trees.
Mission Garden, a recreation of the historic Spanish Colonial walled garden of the San Agustín Mission, was an empty dirt lot in 2012. Now, there are row upon row of trees, teeming with white pomegranates, Mexican limes, Seville oranges, and black and Sosa Carrillo figs.
In 2010, Audrey wrote a grant for the City of Tucson to facilitate work in Mission Garden: the planting of 100 trees, water harvesting workshops, installing irrigation, and holding a September 2012 workshop where the group formed what would become LEAF. LEAF then partnered with the Arizona Community Tree Council to apply for a two-year-long Western Competitive Grant—awarded in 2014 by the USDA and facilitated by the State Forestry Department.
Over the past two years, this $250,000 award has allowed LEAF to create a comprehensive Arizona edible tree database, which lists more than 70 edible tree species with information on water needs, suitable climates, and harvest seasons; and an Arizona edible tree guidebook, available free both in print and as a downloadable file, which will give Arizonans information on how to plant, water, prune, harvest, and process edible trees.
The grant also funded a Tucson-specific guidebook, a website, a statewide conference in Phoenix in 2015, and educational events and tree celebrations, including the Membrillo/Edible Tree Fest to be held at Mission Garden in October.
The goal is to make resources accessible, both for experienced growers and newbies. “We want the layman to be invited, to be able to stick a tree in the ground and get started,” Audrey says. “And we also want to provide more resources for those who want to really dig in.”
LEAF members emphasize right tree, right place, and creating a plan before planting. Audrey says that edible trees “need more care—they need to be pruned and watered, you have to learn how to process [the edibles]. There’s more effort that goes into committing to plant and care for an edible tree.”
Brad Lancaster walks through the urban food forest that lines his sidewalk in the Dunbar/Spring neighborhood. Trees arch over the mulch-covered walking path, creating shade in the 95-degree summer morning heat. When he and his brother, Rodd, moved to the neighborhood in 1994, none of this was here.
Now, shades of green and brown are everywhere, the canopy of trees and understory of vegetation punctuated by bursts of color—the bright fuchsia of cactus fruit, yellow flowers bursting from creosote bushes.
Lancaster is a water-harvesting expert and a founding member of Desert Harvesters, a nonprofit grassroots effort that educates people on planting, harvesting, and processing native plants. Natives are adapted to the landscape so they establish relatively easily and use minimal water. He, his brother, and neighbors obtained trees through Trees for Tucson and learned about planting and harvesting native plants in part by learning from Tohono O’odham elders like Stella Tucker and Clifford Pablo.
Since 1996, Lancaster and other community members have planted 1,400 trees in the Dunbar/Spring neighborhood. In only 20 years, what were dirt paths and empty yards are now a portal for walking and an abundant food forest.
“It’s easier than you think,” Lancaster says. “All the plants here are self-sustaining.”
Lancaster emphasizes the importance of planting the water before you plant trees or other vegetation. How do you “plant water”? You consider the slope of land when planting to make best use of rainwater runoff. You dig basins to encourage rainfall from the street to rush in and provide water to vegetation. You use graywater from your home to help supplement rainwater and encourage plants to thrive.
In his yard, Lancaster fills permeable clay pots buried underground with cistern rainwater, and alternates labeled tubes attached to his outdoor washing machine to direct graywater to different trees.
This landscape is a model for what is possible when people become invested in their surroundings and adapt their lifestyle and palate to the place they call home.
It is also a model for the 180-degree turn Lancaster says must be made in desert landscaping. Typically nowadays, he says, “We plant trees from somewhere else, using water and fertilizer from somewhere else.” Thirty percent of drinking water in Tucson, he notes, is used to irrigate vegetation. But there is an alternative. “Instead,” he says, “let’s plant plants from here, use water from here, and fertilize from here.”
Lancaster picks up a handful of ironwood pods, holding them in his palm, and cracking them open to reveal small dark brown beans. “I call this the peanut of the tree,” he says and hands me one to try. The bean tastes hearty, dense, and a bit salty.
By 2002, Lancaster and others realized they had an abundance of food, but not many people knew how to harvest or process it. They bought a hammermill and started Desert Harvesters. At first, they were trying to adapt to people instead of natural patterns, holding their annual mesquite milling event in October when it was cooler. They now hold it in June which “is more synced with the local ecological rhythm,” when mesquite trees are at their peak of producing.
Desert Harvesters also educates people about how to differentiate quality trees and how to safely harvest. For example, mesquite pods should be harvested before the rain, before they are more susceptible to aflatoxin. They educate people on quality by letting them taste mesquite pods that are sweet, chalky, bitter, dry, and apple-like so they can sample trees in their yard and neighborhood and know where to harvest and which trees to avoid.
Another member of LEAF and Desert Harvesters, Barbara Rose, lives and works at Bean Tree Farm, a 20-acre saguaro/ironwood forest, farm and learning center in the northern Tucson Mountains. She, too, emphasizes the importance of developing what she calls a rainwater budget, where even intermittent rainwater is harnessed as a valuable resource.
On a Saturday evening in July, Rose fills a bowl with salsa made with all local ingredients: Pima lima beans and tepary beans with a tomato and chile paste. Rose, who touts the nutrient density of the beans, takes Palo Verde seeds in their green state, blanches, cooks and serves them with salt, like edamame.
“The desert can feed you,” she says.
When Rose became a caretaker of Bean Tree Farm more than 30 years ago, she began to hear stories from Tohono O’odham elders about the land. She learned the farm area hosted thriving communities of tens of thousands of Hohokam until between 500 and 1,000 years ago. This history is an essential part of the land as are the plants that are native to it. “Why not talk about foods that are native to this place?” she asks. “Why not rewild the urban core?”
“Because I live in an ironwood forest and have watched it disappear over 30 years,” Rose says, “I can contribute that knowledge and take care of this land. Ironwoods can live for a thousand years. They hold the soil, the plants, animals, and insects. That’s what holds the Sonoran Desert together. They won’t if we continue to suck all the water out of the ground.
“A forest is not just trees,” she says. “This is also about the understory, the cacti, the wolfberry, hackberry, the community of plants under and beside that mutually support each other. It’s a template of what a community can be.”
Rafael Routson de Grenade, a research associate at the University of Arizona’s Southwest Center, grew up on a farm outside of Prescott. From a young age, she and her two brothers were exposed to horticulture by their parents and parents’ friends. Her brother Kanin became fascinated by orchards, traveling around the state to study them, and she began her botanical fieldwork with cacti when she was just 15.
For her Ph.D. thesis, de Grenade researched orchards in Baja California. “I was looking at not just the persistence of heritage crops, but also talking with families who had been there for five generations and understanding the cultural relationship with the trees,” she says. “If you go way back to some of the original immigrants, these people are coming from other countries and bringing with them seeds or even young trees to recreate something valuable to them, part of their cultural memory. Food is a tremendous part of that: the flavor, the cooking, the smell, the cultivation is very much a part of people’s lives.”
The longevity of trees preserves a kind of cultural legacy. In the best cases, food technologies—like grafting, planting, pruning, harvesting—are also passed on from generation to generation. “We live in a culture of loss. In terms of our relationship to growing, having hands in the soil, we’ve become more and more removed from that life as a global society,” de Grenade says. “However, I also feel this desire to reconnect … If there is a movement where children or elders can plant a tree, harvest a tree, take care of a tree, I wholeheartedly support it.”
De Grenade and her family recently moved to a small farm in Skull Valley, near Prescott, because she wanted to raise her children on a farm, as she had been, with a close-knit community and connection to the land.
“Edible trees thrive on intergenerational care and stewardship. That process of taking care creates a strong bond between people,” she says. “It carries the stories. A tree holds these things you may or may not be able to hold consciously. When underneath an old tree, you can’t help but think how this tree has experienced so much. The experience of that living being has surpassed the singleness of one life.”
Mounis Hammouda rubs a calamondin lime between his fingers and raises the small orange fruit to his nose. An asylum seeker from Palestine, Hammouda has been in Tucson for four months. Across the way, Jasoda Subedi, a former refugee from Bhutan and now a U.S. citizen, picks limes from the tree. Limes are a necessity for Bhutanese cuisine. Subedi holds up the limes, with stems still attached to prevent the entry of mold, to show Barbara Eiswerth, executive director of Iskashitaa Refugee Network, who nods her head in approval. In the next day or two, staff members and refugees will salt cure the limes.
This is one of the three harvests that Iskashitaa does each week, gleaning fruit and food from private homes and public spaces and converting food that some see as ornamental or inedible into dishes in their own homes and products to sell.
In 2003, Eiswerth started the year-round gleaning program Iskashitaa—in Somali and Maay Maay, it means “working cooperatively together”—to prevent food waste in Tucson while empowering refugees. Refugees bring their agricultural knowledge and skills and are connected with resources and support in the Tucson community.
“What will it take
for people to think of
trees as being a vital part
of the landscape?”
These calamondin trees are next to a Sun Tran building. While the group gleans, two Sun Tran employees come by and sit on a nearby bench for a smoke break. The two seem a bit mystified by the harvest. “I have no idea what the hell those are,” one says to the other.
“This exactly illustrates the problem,” Eiswerth says. People don’t see or know how to work with the bounty right in front of them. For example, high in antioxidants and usable as a lime substitute, calamondins are the least frost sensitive of all Tucson citrus and can be eaten at all stages of development: greening, mature, flowering. Calamondin jam is one of Iskashitaa’s most popular products.
“Fruit waste equals water waste,” Eiswerth says. “Grapefruit is falling all over, enough to fill a swimming pool, but we go and pay our $3.99 for Ruby Reds from Texas. One fourth of the people in Tucson are food insecure. How is that? Why is that?” Eiswerth says change happens from the ground level. “People don’t need to know how to harvest,” she says, “We can teach you. Refugees can teach you.”
Iskashitaa harvests 127,000 pounds of food annually. Fifty percent of this goes to those harvesting, 5 to 10 percent goes to value-added products sold at farmers’ markets, and 40 percent goes to local food banks. They are always looking for innovative ways to use the food they harvest. Eiswerth hands me a sugar stick made with dried calamondins, salt-cured calamondins, citrus-infused sugar, and crushed chiltepines. “Plaza [Liquors] wants to sell these as beer salt,” she says, “and La Cocina is going to make a dish with it.”
Melanie Lenart, a LEAF member and author of Life in the Hothouse, says, “In 50 years with warming, a lot of that food that has certain requirements for chill hours won’t survive.” Being strategic about what varieties of edible trees to plant and planting water for them first is essential, for climate change and food security.
“We are living in the desert and most of the agriculture is likely to be alfalfa or cotton, things you don’t necessarily eat,” Lenart says. “People have to transport food to feed us.”
She notes that transportation of food is a huge contributor to greenhouse gases and that even local food can sometimes have a heavier environmental footprint than we realize. Local figs grown in Arizona may be transported to Michigan, a destination for food sorting, before being loaded back on trucks and stocked in Arizona grocery stores.
“We are so used to walking into a grocery store and buying our food. That’s how many of us grow up,” Lenart says. “Even with the water issue, water comes from the tap. Where did that water start?
“One thing we’ve been seeing around the country is heavier rainfall events,” she says. “A simple way to think about it is that if you have a house and a yard the same size as the house, if you collect water from the roof, you can double your rainfall.”
Lenart, who has taught water harvesting at the University of Arizona, teaches science and agriculture courses at the Tohono O’odham Community College and notes that many of the agricultural strategies that people are returning to now have deep roots in O’odham tradition. “The Tohono O’odham have been using these techniques for hundreds if not thousands of years,” she says. “Clifford Pablo”—a Tohono O’odham tribal member—“watches where the water is flowing and incorporates that into the design of the landscape of the garden. The O’odham have been harvesting mesquite pods for centuries. They’re gluten-free, low-glycemic, good for diabetics.”
Ann Audrey notes that Arizona is distinctive because of its many microclimates and elevations. “So many different trees that can grow in different parts of Arizona now might become important in the next 50 years as other climates throughout the West shift into more extreme heat, drought, or rainfall patterns. We can create the genetic stock now that can be used in times ahead where weather is less predictable and trees that used to survive can’t.”
In a way, the LEAF organization models the sort of expansive forest they are connecting people to and cultivating: the canopy of thousands of trees spread across the state creating one forest, these individuals and their organizations working as one large web. “Each one of us has our own hub and spiderweb of connection and we come together as LEAF network,” Audrey says. “If I visualize that and see the forest at Slide Rock State Park and piñons of northern Arizona and citrus groves in Phoenix and what’s going on in Yuma with commercial orchards and people’s backyard grapefruit trees … Any place a mesquite is growing is producing fruit, or the oaks or junipers are producing. It’s everywhere. You can actually imagine Arizona as a fruiting place.” ✜
Visit Mission Garden for the Membrillo/Edible Tree Fest on Saturday, Oct. 22, from 2-5 p.m.
Lisa O’Neill is a freelance writer in Tucson. Her work focuses on intersections of social justice issues. Visit Lisamoneill.com.
Trees play a critical role in creating healthier, more livable, and prosperous communities, especially in arid, hot cities like Tucson. From cooling the environment through shade and evapo-transpiration to adding beauty to the landscape, trees have tangible value that grows over time. Planting and caring for trees is one of the smartest investments we can make today.
The trees we plant today are tomorrow’s urban forest, a term that defines the entire mosaic of introduced and native trees on both public and private properties. Conditions can be very challenging for trees in the urban environment and we need a variety of trees to choose from to meet a range of goals; we need trees that can withstand heat-absorbing hardscapes and fill different space and microclimate requirements.
Plants native to the Sonoran Desert are beautiful and functional, but pests and disease can attack native trees, too. Heirloom trees make heritage visible and provide deep cultural value, but there are also newer varieties that perform very well. A resilient forest contains many kinds of trees, of varying ages, from diverse genetic sources.
Since 1987, Trees for Tucson has been the urban forestry program of Tucson Clean and Beautiful, Inc., a nonprofit that works to improve the community’s quality of life. Trees for Tucson provides home delivery of professionally grown trees, selected to perform well using low or moderate amounts of water. The LEAF Network developed this list of edible trees suited for the Tucson area. Loquats can do very well if protected from the western sun; plant one to the east of a mesquite. A jujube is tough, and once established, extremely drought tolerant, but it can expand out of control. Kumquats do well in a pot, and can tolerate low temperatures. Carob trees make good shade trees if sheltered from the wind. The native desert hackberry produces sweet edible red berries, makes a great security hedge, and provides excellent bird habitat.
Plant the right tree in the right place. Find the best tree for the goals you want to achieve, and plant it in the type of location it requires. Always plant the water as you plant the tree—pay attention to how water flows on your property and use wells and other landscape strategies to capture rainfall. And don’t forget to mulch, which is crucial to retaining soil moisture.
—Katie Gannon, program director, Trees for Tucson
Visit TreesforTucson.org or call 520.791.3109.