Bean Trees

For one-stop shopping in the Sonoran Desert, a mesquite tree is your best bet to find everything you might need, whether it be food, fuel, building supplies, medicine, rope, and yes, even diapers. These trees were so valued by traditional cultures in the southwest deserts that families claimed certain mesquite groves, or bosques, as well as especially productive individual trees, as their territory. One mature tree may produce between 40 to 100 pounds of bean pods in a good season, the basis of a healthy diet for many tribes. The pods were stored through the winter and ground into flour when needed to make cakes, porridge and sweet drinks throughout the year. For thousands of years, desert people have gathered mesquite wood for building shelters and making fires, sap for dyes, roots for fiber and leaves for medicinal tea. The diapers were made by pounding sheets of the fibrous bark into a soft cloth that would absorb any “leaks.”

The human relationship with mesquite is not quite so benevolent everywhere it grows, however. Many ranchers consider it to be a pest, since it will thrive wherever cattle roam, replacing valuable grasslands. The irony is that cattle feast on mesquite pods, and then deposit the beans in cow pies, a perfect environment for the seeds to germinate and grow.  Thus, more cattle on the range is better for mesquites. Paleontologists have deduced that cattle may be replacing the role of other large mammals that once roamed the southwest, such as camels, giant sloths and mastodons. After the Pleistocene extinctions about 10,000 years ago, mesquite bosques contracted to waterways and washes, where year round moisture and seasonal flooding ensured their success. But without passage through the guts of large mammals that travel long distances between waterways, the seeds were no longer distributed onto uplands.

Even though a healthy bosque provides shade and fodder for cattle, an aggressive campaign to eradicate mesquite in favor of grasslands ensued through the 1900’s. Combined with habitat destruction for agricultural, industrial and urban development, plus harvesting of trees for firewood and lumber, wild mesquite bosques are now considered somewhat rare.

Fortunately, the versatile bean tree has become a popular landscaping species over the past few decades, and is now grown and planted widely through the arboriculture trade. Velvet mesquite (Prosopis juliflora) is the most common in the Phoenix area, shading many parking lots and suburban tracts with their graceful, contorted stems. The return of mesquite to urban areas is also a boon to wildlife. Rabbits, coyotes, quails, javelina and deer also feed on the bean pods. Dozens of bird species nest and forage for insects in mesquite limbs. Mesquite leaf letter enriches soils with nitrogen, which, combined with shade, makes them excellent “nurse trees” for many kinds of plants. Plus, over sixty species of insects have been documented as visitors to mesquite flowers, gathering the abundant pollen and nectar to propagate their own offspring. In the spring, when long tassels of flowers dangle from the branches, a bean tree literally hums with life.  

According to the locavore food movement, which promotes the use of regionally adapted and native foods, mesquite could be the key to a more abundant and nutritive future for desert dwellers. If you are lucky to have a mesquite in your yard, you can rake up the pods to use as an alternative to mesquite wood for grilling and grind them into flour to use in baking. Here's how:

Prepare bean pods: Collect and rinse pods with clean water and dry in the sun. You can accelerate drying by putting them in the oven at the lowest temperature (~150F) for 2-4 hours. The more crispy the pods, the easier it is to grind them into flour.

Make the flour: If you want to be very traditional, get out the mano and metate or a mortar and pestel! However, you can also grind the bean pods in a blender. Just  put about 15 pods in at a time for about 30 seconds. Sift with a fine sieve and store the flour in the freezer until ready to use. Make sure you are sifting out the hard, bitter seeds.

Bake: The traditional cake or cookie was a simple mixture of flour and water, made into round flat patties and dried in the sun. To use mesquite in baking, just replace ¼ of the amount of flour called for in your recipe with finely ground mesquite meal.

Steep Tea: A sweet tea can be made by soaking some of the flour in water and then straining off the pulp….perfect to serve with cookies!

To learn more about the history and ethnobotany of mesquite, look for these books:

Gathering the Desert by Gary Paul Nabhan

Medicinal Plants of the American Southwest by Charles W. Kane

And check out this website: Desert Harvesters (www.desertharvesters.com) in Tucson hosts mesquite pod milling events every year, as well as being a resource for numerous workshops and publications on native plant foods.