Trees

Mesquite

Mesquite
Scientific Classification
Family: Fabaceae
(Same as Palo Verde, Mexican Bird of Paradise and Acacia)
Genus:Prosopis

A variety of Mesquite trees are found in the Tucson area, some native to Arizona and some imported. Most can be cultivated to grow to about 20 to 30 feet in height although in nature they more typically grow much shorter with many trunks.

Most healthy Mesquites can bear leafs most or all year long providing welcome shade during the hot summers. Tucson's annual rainfall is enough to keep Mesquites alive but young Mesquites can benefit from infrequent deep watering under the dripline.

Because Mesquites are legumes, they fix nitrogen into the soil from the air so fertilization is generally not required. In fact, adding nitrogen to the soil can encourage new growth causing the tree to become top-heavy and easily blown over in storms.

As a Food Source

Bean pods can be ground into flour to make bread. Mix about 25% to 50% mesquite flour with other flour. It can also be used in pancakes, muffins, biscuits, and cookies or to season meat, poultry, or fish. The blossoms of Mesquite trees provide a source of nectar for bees to produce mesquite honey.

Propagation

Seed pods should be picked as soon as the seed rattles in the pod and the seeds then stored in a dry place. Mesquite seeds can remain viable for many years.

Bruchid Beetles lay eggs on developing pods then when the eggs hatch, the larvae burrow into the pods and eat the seeds. They later emerge from the pods by boring small holes. Freezing or fumigating the pods can kill the beetles. Otherwise, up to 75% of seeds are typically destroyed by the beetles.

Before planting, the seeds must be scarified by chipping, cutting, sanding, acid treatment, or exposing to boiling water. Soak the seeds in water at 90°F for six hours. Temperatures between about 90° F and 100° F are best for germination. Plant the seeds 1/4 inch to 1/2 inch deep in a well drained sandy soil mix.

Propagation by cuttings or layering may be possible, but doing so reduces the genetic diversity making the species more susceptible to disease.

Transplanting

Dig a hole of a depth about equal to the height of the root ball and at least three times as wide. Be sure not to disturb the soil any deeper directly under the location where the tree will be replaced to keep it from sinking. Rapidly so as to prevent the roots from drying out, remove the tree from the pot, place it in the hole, and backfill the hole with the original soil. The original soil without amendments should be used so that the roots will spread outward as they grow rather than coiling in circles inside the hole. Be careful not to cover the trunk of the tree higher than the original soil line and slope the backfill soil away form the trunk for drainage. Form a watering basin at the edge of the dripline. As the tree grows and the dripline expands, gradually move the water basin farther out.

The tree should be watered infrequently but deeply during hot weather for the first 2 to 3 years. Excessive watering can loosen the soil and make the tree top heavy causing it to blow over in a storm.

Mesquites Native to the Tucson Area

Mesquites Introduced to the Tucson Area

Mesquite Hybrids

Other Mesquites Around the World

Palo Verde

Palo Verde
Scientific Classification
Family: Fabaceae
(same as Mesquite, Mexican Bird of Paradise and Acacia)
Genus:Parkinsonia (previously Cercidium)

The Palo Verde tree (the State Tree of Arizona) is a desert-adapted tree which has leaves only after heavy rains. Most of the photosynthesis is carried out in the green twigs and branches hence the name Palo Verde which is Spanish for "green stick". In a certain elevation range around Tucson, the Palo Verde tree provides an environment conducive to propagation of the Saguaro cactus.

Palo Verde Species

Palms

Date Palm
Scientific Classification
Family: Arecaceae
Genus: Phoenix
(Date Palm)
or
Washingtonia
(Mexican Fan Palm)