Tetradymia canescens

Common Names

Gray Horsebrush, Spineless Horsebrush, Grey Horsebrush, Common Horsebrush

Summary

Gray horsebrush, also known as spineless horsebrush, is a spineless, multi-branched shrub native to arid western North America. It typically grows 10–80 cm tall and features dense, silvery-gray foliage with narrow lance-shaped leaves up to 3 cm long. At branch tips, inflorescences usually include 3–6 heads, each head with four tubular yellow flowers 7–15 mm long; flowering occurs in summer. The plant is fire-adapted, resprouting vigorously after fire and increasing in herbage and seed production post-fire, contributing to its dominance in post-burn landscapes.

In cultivation, it prefers sunny sites with sandy or well-drained soils and is highly drought-tolerant, commonly used in dry landscaping and habitat restoration within sagebrush scrub and pinyon–juniper communities. It is hardy to zone 4 and can be propagated from seeds sown in spring or cuttings rooted in sandy soil during the growing season; maintenance is minimal. It is toxic to sheep, causing photosensitivity and abortion, so grazing should be avoided; fire management guidance notes often avoid burning to reduce spread due to rapid resprouting and abundant postfire seed production.

Lifecycle

Perennial

Height

2.5-3 feet

Spread

0.5-3 feet

Hardiness Zones

Zones 4

Sunlight Requirements

Ideally full sun; tolerates partial shade.

Soil Type

Sandy, well-drained, coarse-textured soil

Soil Drainage

Well-drained soils

Soil pH

7-8

Bloom Color

Yellow to cream-colored

Bloom Time

Summer

Foliage Color

Gray to white, with silvery-gray tones

Fall Foliage Color

Yellow

Leaf Lifecycle

Deciduous

Growth Rate

Slow

Seasons of Interest

Spring, Summer, Fall

Propagation Methods

Seeds, Cuttings, Division

Attracts Wildlife

Attracts bees and other pollinators