Senna covesii
Coues' senna
Southwestern United States and northern Mexico
Attracts PollinatorsAttracts ButterfliesDeer ResistantDrought TolerantContainer Friendly
Native to North America
Overview
Senna covesii is a low, mounding perennial subshrub growing 1 to 2 feet (30 to 60 cm) tall and wide, with gray-green, hairy stems and foliage. The pinnate leaves carry two to three pairs of oval leaflets, each 0.5 to 1 inch (1.3 to 2.5 cm) long, covered in soft hairs. From spring through fall, and especially after rain, it bears clusters of five-petaled yellow to yellow-orange flowers about 0.75 inch (2 cm) across, with prominent brown anthers. The flowers ripen into flat, curved seed pods 1 to 2 inches (2.5 to 5 cm) long. It grows on sandy and gravelly desert flats, washes, and roadsides across the Sonoran and Mojave deserts. The plant tolerates heat and drought, blooming in flushes tied to rainfall, and dies back in hard frost. It serves as a larval host for sulphur butterflies and a nectar source for bees. It needs full sun and sharp drainage and is short-lived in wet or shaded sites.
Native Range
Native to the Sonoran and Mojave deserts of the southwestern United States, including Arizona, southern California, New Mexico, and Texas, and into northern Mexico. It grows on sandy and gravelly flats, desert washes, and roadsides.Suggested Uses
Used in desert and xeriscape gardens, native plantings, and pollinator gardens on dry sites. It serves as a larval host for cloudless sulphur and other sulphur butterflies and a nectar source for bees. The low mound suits rock gardens and low-water borders.How to Identify
Appearance
Size & Dimensions
Height1' - 2'
Width/Spread1' - 2'
Bloom Information
Flowering occurs in flushes from spring through fall, generally March through October, strongest after rain. Clusters of yellow to yellow-orange, five-petaled flowers open above the foliage. Each flush lasts a few weeks. Flat seed pods follow each bloom.
Detailed Descriptions
Flower Description
yellow to yellow-orangeFoliage Description
gray-greenGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grow in full sun in sandy, gravelly, or rocky soil with sharp drainage. Senna covesii tolerates extreme heat and drought and needs little water once established. A soil pH from 6.5 to 8.0 suits it. Occasional deep watering in summer extends flowering. It is hardy in USDA zones 8 through 10 and dies back in hard frost. Wet, heavy, or shaded ground shortens its life. Little feeding is needed in lean desert soils.Pruning
Cut back frost-damaged or leggy stems in late winter to renew compact growth. Light shearing after a bloom flush can prompt rebloom. Spent pods can be removed to limit self-sowing. The plant resprouts from the base after cutting.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
winter
Container Growing
✓ Suitable for container growing
Minimum container size: 3 gallons