Actual size and flowering may vary slightly based on season.
Purple Muhly
Purple Muhly is a native bunchgrass that grows wild in southeastern Arizona and turns purple when it blooms in late summer and fall. It forms a tidy, airy mound of fine gray-green leaves about 2 to 3 feet tall. The purple plumes fade to tan as the seed sets. Plant it in groups for a soft groundcover on banks, slopes and open sunny beds.
Best for: Mass plantings and groundcover in open sunny areas, banks and rock gardens, native plantings, and fall color in a low-water yard.
Plant it in groups in open, sunny areas, about 2 to 3 feet apart, and the clumps read as one soft sweep. In fall the whole group turns purple.
It grows wild on rocky, gravelly slopes, and it is planted as a bank cover and in rock gardens. Muhly grasses planted in a dense mass help hold soil on slopes.
Purple plumes rise above the leaves in late summer and fall, then fade to tan as the seed sets. Birds eat the seed, so leave the plumes standing until the late winter cutback.
Extra water makes it bigger but raises the chance of crown rot, so the soil must drain. Repeated shearing through the year weakens it, so cut it back only once a year.
- Mass planting2-3 ft apart
- Plant to plant2-3 ft apart, center to center
Water new plants regularly while they get rooted. New plants need extra water for their first year or two.
Once rooted, a deep soak every 1 to 2 weeks in summer keeps it full and blooming. It survives on less but browns out. More water also makes it bigger, so do not overdo it.
Cut it back once a year in late winter, down to a few inches, before new growth starts. Some years you can skip it. Avoid shearing it through the year.
Plant it where water drains away. Wet soil around the crown can lead to crown rot.
Drainage test first. Dig the hole and fill it with water. If water is still sitting in the hole a day later, you likely hit caliche, clay or hard soil, so fix the drainage before planting. If it drains very fast, the soil is sandy. Standing water around roots is a common reason new plants fail.
Weed cloth. Cut it away from the planting hole and where the roots will spread. Remove any plastic sheeting completely, since it keeps water and air out of the soil.
Rock or decomposed granite with no soil underneath. Bring in soil close in texture to your native soil, mix it with the soil below, and build up enough depth for roots before planting.
If you can break through. Use a breaker bar, pick, or jackhammer. Dig through the caliche and break out the solid chunks. Backfill with the soil you dug out, with no compost or manure in the hole. Confirm drainage before planting.
If you cannot break through. Dig narrow holes through the hard layer beside the root ball, not under it, and refill them with the same soil, not gravel. If it still will not drain, plant on a low mound of the same soil.
Root ball. Check the outside edges for any roots circling around. Loosen or cut those so they grow outward. Do not break up the center of the root ball.
Depth. The top of the root ball should sit at or just slightly above the surrounding soil level. Planting too deep can lead to rot and kill the plant.
Drip emitters. At planting, put the emitters on the root ball, on different sides of the plant. After about 2 months, move them to the outer edge of the root ball. Over the first year, add emitters farther out toward the edge of the branches as roots grow. Once a plant is rooted, never water only at the trunk.
How big does purple muhly get?
It usually grows about 2 to 3 feet tall and 2 to 4 feet wide. With generous water it can grow larger than people expect, up to about 5 feet, so give it room.
When does purple muhly bloom?
It blooms from late summer into fall, roughly August through November. The plumes open purple, then fade to tan or blonde as the seed sets.
Is purple muhly the same as Nashville grass?
Nashville is a named selection of the same species, and it is also sold as purple muhly. It is listed at 1 to 3 feet, while the plain species is listed at 2 to 5 feet. Pick Nashville for tight spots.
How is purple muhly different from deer grass?
Purple muhly is smaller, about 2 to 3 feet, and its plumes turn purple. Deer grass grows 3 to 5 feet tall and wide with tan flower spikes.
Is purple muhly native to Arizona?
Yes. It grows wild on rocky slopes in southeastern Arizona, southern New Mexico and west Texas, and south into Mexico.
How often should I water purple muhly?
Water new plants regularly while they get rooted. Once rooted, a deep soak every 1 to 2 weeks in summer keeps it full. It survives on less but browns out and blooms less.
Can purple muhly grow in shade?
It takes some shade, but it grows flatter there. Plant it in full sun for the most upright shape and the best purple color.
When should I cut back purple muhly?
Cut it back once a year in late winter, before new growth starts, down to a few inches. Avoid shearing it through the year, which weakens the plant.
What soil does purple muhly need?
It handles most Valley soils, but it grows best in soil that drains. Wet soil raises the chance of crown rot, so avoid low spots where water sits.
How cold hardy is purple muhly?
It is rated to about -10°F. In the wild it grows at higher elevations in southeastern Arizona.
Does purple muhly have pest problems?
No pests or diseases are known to bother it in central Arizona.
Purple Muhly for sale in Arizona, delivered to you
Purple Muhly is the plain native species of muhly grass that grows wild in southeastern Arizona. It forms an airy clump about 2 to 3 feet tall, with purple plumes in late summer and fall. This page covers size, spacing, bloom, water, the yearly cutback and how it compares with Nashville grass and deer grass.
Sourced from trusted Arizona growers and delivered directly to your door, job site, or property. We deliver across the Valley and to nearby towns, and quote delivery anywhere else in Arizona.
Purple muhly vs Nashville grass
Nashville is a named selection of purple muhly and is listed at 1 to 3 feet. The plain species is listed at 2 to 5 feet, so it fills a larger space. Both turn purple in fall.
How big does purple muhly get in Phoenix?
Plan on about 2 to 3 feet tall and 2 to 4 feet wide. With generous water it can reach about 5 feet, larger than many people expect.
How far apart to plant purple muhly
Plant it about 2 to 3 feet apart, center to center, for a mass planting.
When does purple muhly turn purple?
It blooms from late summer into fall, roughly August through November. The plumes open purple and fade to tan as the seed sets.
Watering purple muhly in the Valley
Water new plants regularly while they get rooted. Once rooted, a deep soak every 1 to 2 weeks in summer keeps it full. Soil that drains keeps crown rot away.
How to cut back purple muhly
Cut it back once a year in late winter, down to a few inches, before new growth starts. Repeated trims through the year weaken it.
Is purple muhly native to Arizona?
Yes. It grows wild on rocky slopes in southeastern Arizona, southern New Mexico and west Texas, and south into Mexico. Seed-eating birds feed on the ripe plumes.
We deliver across the Valley, from Phoenix, Scottsdale and Mesa out to San Tan Valley, Maricopa and Casa Grande, and up to Prescott, Sedona, Payson and Globe. See delivery areas and rates.