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Smoke Tree

Psorothamnus spinosa

false

1 Gallon

Smoke Tree

Out of stock

20'x20'

Sizes:

Smoketree — Psorothamnus spinosus

Also known as: Smoke Tree, Indigobush, Smokebrush, Smoke Thorn
Synonym: Formerly classified as Dalea spinosa

Smoketree is a spiny, deep-rooted, almost leafless legume tree native to the Colorado Desert and select regions of the Mojave Desert. A signature species of the Coachella Valley landscape, it is most often found in sandy desert washes, disturbed alluvial fans, and along arroyos and roadsides. Though its broader range includes southern California, Arizona, Baja California, and parts of Nevada, its habitat is highly specific to well-drained, loose, sandy soils and it does not tolerate compaction or clay.

This distinctive perennial tree grows up to 20 feet tall and typically forms an irregular, open-canopied silhouette. With silvery-gray stems covered in fine, whitish hairs and very small or absent leaves, its name “Smoketree” comes from its hazy appearance in the landscape. The foliage is aromatic when crushed. Despite its unconventional form, it offers striking seasonal interest. In early summer (June), the tree erupts into dramatic bloom with clusters of vivid violet to indigo-blue flowers along its lateral stems, contrasting beautifully with its muted structure.

Following flowering, Smoketree produces small, hard-seeded pea pods, and as a legume, it contributes to nitrogen fixation in the soil. Its taproot allows it to survive on rainfall alone once established, making it highly drought tolerant, though this same trait makes it difficult to transplant. It is a frequent presence in Joshua Tree National Park, where it plays an important role in wash dynamics and ecological succession.

Wildlife Value

Host Plant: —
Nectar Source: Verified for numerous generalist pollinators including native bees, honeybees (Apis mellifera), flies, moths, butterflies, and hummingbirds such as the Costa’s Hummingbird (Calypte costae), which is known to visit its blooms.
Bird Resources: Nectar; Seeds; Shelter
Bird Species: Costa’s Hummingbird (Calypte costae); Black-throated Sparrow (Amphispiza bilineata); Verdins (Auriparus flaviceps); White-crowned Sparrow (Zonotrichia leucophrys) [winter]; California Towhee (Melozone crissalis)

Plant Care

Native region:

Local Native

Water needs:

Very Low

Exposure:

Full Sun

Mature size:

20'x20'

Growth rate:

Slow

Flower color:

Purple; Blue

Flower season:

Summer

Pruning:

None

Cold Hardiness:

20 Degrees

Nectar-producing:

Yes

Attracts pollinators:

Yes

Nighttime pollinators:

Butterflies or Moths:

Yes

Monarchs:

Larval host:

Yes

Bees:

Yes

Bats:

Birds:

Yes

Nest site:

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.