PL. —Aristida purpureaBotanical illustration — drop image
Aristida purpurea

Purple Three-awn

SummerFall
5a10bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Peak bloom
Summer
Peak bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

Aristida purpurea is a native warm-season bunchgrass distributed across the central and western United States, from the Great Plains into the Sonoran Desert and northern Mexico. Each seed bears three slender awns that flush purple-red in late summer and persist into autumn, giving the plant strong seasonal presence in dry and native landscapes.

It establishes readily from seed and tolerates poor, sandy, or rocky soils with minimal water, conditions that exclude most cultivated plants. It is a natural component of short-grass prairie and desert grassland communities and often the first grass to colonize disturbed or overgrazed ground. Seeds are taken by ground-feeding sparrows, quail, and other birds through winter. In designed landscapes it performs well in xeriscape plantings, dry meadow mixes, and on exposed slopes where erosion control and soil stabilization are priorities. Prefers a soil pH near neutral and requires no supplemental fertilizer; rich soil promotes lax, weedy growth.

Care guide
SunFull sun
WaterLow
SoilWell-drained, sandy, dry
Spacing12–18 in
Height12–30 in
Zone5a – 10b
Native RegionAZ, AR, CA, CO, ID, KS, LA, MT, NE, NV, NM, ND, OK, OR, SD, TX, UT, WA, WY
Direct sow
Seasonal tasks
spring
cutCut back previous year's stems to 3–4 inches before new growth resumes in early spring.
sowDirect sow seed onto bare, cleared soil after last frost; press lightly into the surface without deep coverage.
summer
watchMonitor surrounding beds for self-sown seedlings; pull unwanted plants while still small and shallow-rooted.
watchAwn color peaks in late summer; leave stems standing through winter to supply seed for ground-feeding birds.
fall
sowSow seed directly in fall for natural cold stratification and improved germination the following spring.