Pink Muhly Grass Plant Profile

Pink muhly grass in garden

Yaorusheng / Getty Images

There are plenty of ornamental grasses to choose from, but few are as spectacular and yet low-maintenance as pink muhly grass. Sometimes also referred to as hairawn muhly, this perennial species of grass is native to the eastern United States, stretching from Massachusetts to Florida and as far as west as Texas and Kansas. Today, however, the species is endangered in New Jersey, Connecticut, Maryland, and Indiana. It’s extirpated in Pennsylvania, and presumably also Ohio.

Preferring warm, dry climates, this blooming grass is popular for landscaping both residential areas, highway medians, and parks. In the spring and summer, the slender, long shoots of grass are green in color. As the fall approaches, the plant produces soft, fuzzy flowers in pink or pinkish-red hues which are often compared to the appearance of cotton candy. The beauty and abundance of these bloom clusters makes the plant an attractive addition to any garden, especially since the flowers appear at the end of the growing season and make for a spectacular final finish in the fall. 

Pink muhly grass in bloom
Pink muhly grass in bloom. Zen Rial / Getty Images
Pink muhly grass with seeds
Pink muhly grass with seeds. caoyu36 / Getty Images
Botanical Name Muhlenbergia capillaris
Common Name Pink muhly grass
Plant Type Perennial
Mature Size 1 to 3 feet tall and 2 to 3 feet wide
Sun Exposure Full to part sun
Soil Type Dry and well-drained
Soil pH Slightly acidic
Bloom Time Fall
Flower Color Pink, pinkish-red
Hardiness Zones 6 to 9
Native Area Eastern and southern North America

How to Grow Pink Muhly Grass

Pink muhly grass is not only beautiful, but also low-maintenance. It doesn’t take much in the way of time and attention to make the most of this showy ornamental grass. These plants are best put in the ground in the spring or in the fall—at least a month before the initial frost is expected. Be sure to provide adequate spacing of at least several feet in between plants for sufficient airflow and in order to avoid a fungal infection known as tar spot.

These perennial grasses will actively grow their shoots through the spring and summer before producing plumes of pink or reddish seed-bearing flowers in the fall. As winter approaches, the flowers lose their color but the dried-out plumes continue to offer visual appeal throughout the dormant season.

Aside from occasional pruning and dividing the plants every few years, pink muhly grass rarely requires much gardener intervention. These plants thrive in sunlight, prefer dry, well-drained soil, and rarely need fertilizer for healthy, abundant growth. 

Light

Pink muhly grass needs to be planted in part sun or full sun conditions. It can tolerate some shade, for proper growth and blooming, does require at least several hours of sunlight each day. 

Soil

The most important thing to know is that this type of grass requires dry, well-draining soil. If the soil becomes too wet or boggy, pink muhly grass will suffer.

In terms of soil pH, this plant prefers slightly acidic to neutral soils. Soil with too high of a pH level will be damaging to the plant.

One factor that pink muhly grass tolerates exceptionally well is salinity. So soil with elevated salt content due to irrigation, mineral weatherization, road salt, etc. are generally not a problem for growing this type of grass.

Water

Once pink muhly grass is established, it doesn’t require much in the way of regular irrigation. It’s considered to be drought-tolerant and prefers dry soil. So don’t run for the watering can if you experience short bouts of dry weather. The deep roots of this grass plant enable it to thrive even in dry, hot conditions.

However, if the soil surrounding the plant becomes dry to a depth of 2 inches or more, give the plant about an inch of water. As mentioned, be sure that the soil is well-draining and doesn’t become overly saturated. 

Temperature and Humidity

Pink muhly grass flourishes in warm, dry weather. While it’s native as far north as Massachusetts, it’s often found in abundance in hot, dry climates where it grows well and returns year after year. And while this plant has no problem with warm weather, too much humidity, can affect it negatively and may increase susceptibility to tar spot, a fungal plant disease.

This plant is only hardy to USDA zone 6, meaning it can’t tolerate winter temperatures much below -10 degrees without dying off. In such cases, there are hardier options for cold weather ornamental grasses. 

Fertilizer

Most ornamental grasses thrive without the addition of fertilizer. Too much nitrogen can even have a detrimental effect on plants like pink muhly grass and cause the shoots to become limp. It’s best to do a soil test to determine whether or not your soil nutrients need a boost. 

Propagating Pink Muhly Grass

One stand of showy pink muhly grass can become a real show-stopping display by propagating the plant. These plants are relatively easy to multiply by either seed collection or division. In fact, dividing pink muhly grass plants typically becomes necessary every few years to keep order and necessary spacing between individual plants. Otherwise, the plant continues to spread and a dead area can form in the center of the clump.

To propagate by division, follow these steps:

  1. Using a shovel or spade, dig around the perimeter of an individual plant and then be sure to dig deep enough under the plant to free the root ball.
  2. Split the plant into two or three equal parts, depending on the size of the root ball. Keep in mind that ornamental grasses may have very dense root systems. It might take a sharp tool or even a chainsaw to divide the root system. Use caution and personal protective equipment.
  3. Place one division of the plant back into the original hole. The remaining sections can be relocated or passed along to a friend for planting in their garden.

To propagate by seed, you’ll need to collect the brown seeds that collect in the flower plumes. Once the brilliant pink or reddish hues have faded from the flowers in late fall, it’s time to collect the seeds. You can comb the plumb to release the seeds—leaving the dried flowering grass intact for some visual interest through the winter season.

Plant the seeds in early spring, either indoors or you can direct sow them outside in a sheltered area if the climate is favorable enough. Pink muhly grass seeds need light in order to germinate, so sow them on a layer of soil but don’t cover them. Mist with water to maintain moisture until the seeds begin to sprout.

Toxicity of Pink Muhly Grass

Most ornamental grasses are not toxic to humans or animals and this is also true for pink muhly grass. It’s safe to plant in areas frequented by dogs, cats, or other small animals and doesn’t pose any significant risks if ingested. 

Pruning

This perennial plant will benefit from being cut back in the late winter or early spring, before the growing season begins. Be sure not to cut too close to the crown of the plant—a distance of at least 3 to 4 inches should be sufficient.

Avoid pruning this plant in mid-to-late summer, since doing so can interfere with the production of the beautiful plumes of flowers that pink muhly grass is known for.