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Screwbean Mesquite

Prosopis pubescens

true

5 gallon; 15 gallon

Screwbean Mesquite

In stock

15-30'x15-30'

Sizes:

Screwbean Mesquite – Prosopis pubescens
Also known as: Tornillo, Screwbean, Tornillo Mesquite

Screwbean Mesquite is a small, shrubby, multi-trunked tree in the legume family (Fabaceae), native to the Sonoran, Mojave, and Chihuahuan deserts. In California, it is most commonly found in the Colorado Desert, especially along desert washes, bottomlands, and seasonal floodplains. It is easily identified by its tightly coiled, screw-like seed pods—a distinctive and unmistakable feature that gives the tree its common name, tornillo (Spanish for "screw").

This deciduous tree typically reaches 10–20 feet tall, with pale blue-green, finely divided leaves and paired spines on its branches. In spring, fuzzy yellow flower spikes bloom, followed by the curled seed pods. These sweet pods were traditionally used as a food source by Indigenous peoples, who ground them into flour or roasted them whole. As the tree matures, it develops attractive, shaggy bark and a gnarled form. With irrigation, it can be pruned into a small canopy tree, though it usually grows in a shrubby, spreading habit.

Like most mesquites, P. pubescens has a deep taproot and thrives in full sun and well-drained soil, though it requires more regular summer irrigation in the low desert. In nature, it is found in areas with periodic flooding or where subsurface water is present. Screwbean Mesquite is an excellent wildlife plant that supports a wide range of desert species. Its seeds are a food source, its flowers attract beneficial pollinators, and its thickets provide cover and shelter for desert mammals and birds.

Wildlife Value
Host Plant: Marine Blue (Leptotes marina); Reakirt’s Blue (Echinargus isola); Ceraunus Blue (Hemiargus ceraunus); Palmer’s Metalmark (Apodemia palmeri)
Nectar Source: Marine Blue (Leptotes marina)
Bird Resources: Seeds
Bird Species: Gambel’s Quail (Callipepla gambelii)
Other Wildlife: Jackrabbits; Ground Squirrels; Pocket Mice, Desert Tortoises — use Screwbean Mesquite for food and shelter

Plant Care

Native region:

Sonoran Desert; Mojave Desert

Water needs:

Low

Exposure:

Full Sun

Mature size:

15-30'x15-30'

Growth rate:

Slow - Moderate

Flower color:

Yellow

Flower season:

Spring; Winter

Pruning:

For first several years prune lightly and frequently, pinching back unwanted side branches to encourage faster development of tree form.

Cold Hardiness:

15 Degrees

Nectar-producing:

Yes

Attracts pollinators:

Yes

Nighttime pollinators:

Butterflies or Moths:

Yes

Monarchs:

Larval host:

Yes

Bees:

Yes

Bats:

Birds:

Yes

Nest site:

Yes

Nest materials:

Rabbit-resistant:

Yes

Tortoises:

Growing Plants in the Desert — Important Information

The information presented here is, to the best of my knowledge, accurate and based on reliable research, personal experience in my own garden, observations from other gardens I’ve visited, and time spent studying plants in their native habitats. I always welcome your feedback and experiences to help me continue educating others!

Cacti:
In my experience, cacti are much happier in filtered shade here in the low desert of the Coachella Valley. Their colors are more vibrant and they tend to bloom more profusely, especially the non-native varieties. If you look closely at how our native barrel cactus and beavertail prickly pear grow in the wild, you’ll often find them tucked among rocks or beneath the shelter of creosote and other shrubs.

⚠️ A note of caution: Cacti and succulents are often illegally collected from the wild, which not only damages plant populations but also disturbs entire ecosystems. In some cases, wild populations of cacti have even gone extinct because of this practice. When purchasing these plants, always be sure they’ve been legally obtained. Look for nursery-grown stock or plants with a native plant certification, and keep that documentation for your records.

Light Requirements:
In our desert (Sonoran/Colorado), “full sun” doesn’t always mean what you might think. Many so-called full-sun plants benefit from and actually appreciate some late-afternoon filtered light—especially during the intense summer months.