Muhlenbergia

( mew - len - BERG - ee - uh )

At-A-Glance Information

This genus of perennial grasses, commonly called Muhly or Muhly Grass, includes species which need full sun to light shade and little water to perform well in the garden. These grasses have narrow leaves, and are evergreen in areas that experience mild winters (turning brown or tan in response to hard freezes). Use these ornamental grasses in modern, natural, or drought-tolerant landscapes in mass plantings, mixed borders and edging, or as specimens to create interest, texture and movement.

Muhlenbergia Species and Varietals

Muhlenbergia is a genus in the plant family Poaceae and includes between 150 and 180 species. These grasses are closely related to Sporobolus (Dropseed). The best growing zones for Muhlenbergia vary depending on the species. For more information, see the descriptions below. To find your zone, click here: Zone Map.

Muhlenbergia capillaris (Pink Muhly, Pink Muhly Grass, Gulf Muhly, Hair-Awn Muhly, Hair Grass)
This species grows well in UDSA hardiness zones 5-9 or Sunset growing zones 4-24 and is native to the eastern United States. Foliage is dark green and forms a mound 3 feet tall and 6 feet wide. Feathery reddish flowers bloom an additional 2.5 feet above the foliage. Cut back in late wintertime for fresh growth in spring. Variety 'Regal Mist' (also called 'Lenca') has deep rose-pink flowers.

Muhlenbergia dubia (Pine Muhly, Mexican Deer Grass, Pineland Muhly)
This grass is native to Arizona, Texas, New Mexico, and northern areas of Mexico. and grows well in USDA hardiness zones 6-10 or Sunset growing zones 3b and 7-24. This plant forms dense tufts 2-3 feet tall and wide, with fine-textured leaves and cream-colored flowers that bloom in summer and fall. Needs well-draining soil.

Muhlenbergia dumosa (Bamboo Muhly, Faury Bamboo Grass, Muhly Grass)
To 3-6 feet tall and just as wide, this plant resembles Bamboo, and grows well in UDSA hardiness zones 8a-11 or Sunset growing zones 8-24. It is native to Arizona and Mexico. Stems hold narrow green leaves, and branching flower clusters appear in springtime, though they are relatively insignificant.

Muhlenbergia emersleyi (Bull Grass, Gooding's Muhly)
This Arizona, Mexico, and Texas native grass does well in USDA hardiness zones 6-10 or Sunset growing zones 2-24 and has glossy green leaves. Individual plants reach 1.5 feet tall and 3-4 feet wide, and produce spikes of purple-red flowers in summer and fall that fade to cream with age. Cultivars of this species include 'El Toro' (with dense rose-purple flower spikes to 2-3 feet tall) and 'Madrone' (to 18-24 inches tall with purple feathery seed heads.

Muhlenbergia lindheimeri (Lindheimer's Muhly, Big Muhly)
Best in USDA hardiness zones 6a-11 or Sunset growing zones 6-24 and native to Texas and Mexico, this plant forms a clump of soft blue-green foliage 5 feet tall and just as wide. Flower spikes rise 2 feet above leaves in fall, and blooms are amber. These grasses are semi-evergreen in mild-winter areas, but will die to the ground in wintertime elsewhere.

Muhlenbergia porteri (Bush Muhly, Porter's Muhly)
This species of Muhly grows well in USDA hardiness zones 7-11 or Sunset growing zones 3, 7-14 and 18-24. It is native to the southwestern United States and northern areas of Mexico. It reaches 3 feet tall and just as wide, with blue-green stems and foliage. Seed heads are pink-purple and put on a show in late summer through fall.

Muhlenbergia pubescens (Soft Blue Mexican Muhly, Soft Muhly)
Native to central Mexico, this species grows well in USDA hardiness zones 9a-11 or Sunset growing zones 8-24 and forms a foliage clump a foot tall and two feet wide of downy blue-green foliage. Light blue flowers form on spikes and age to amber. Light frosts will turn foliage purple-red, and harder freezes will kill the grass to the ground.

Muhlenbergia rigens (Deer Grass, Meadow Muhly)
Best in UDSA hardiness zones 7-11 or Sunset growing zones 4-24, this grass is native to California to Texas and south into northern Mexico. It has bright green leaves and reaches up to 4 feet tall and wide. Purple or yellow flower spikes emerge in fall, and as they age they tend to droop.

Muhlenbergia rigida (Purple Muhly, Purple Muhly Grass)
Grows in USDA hardiness zones 6-10 or Sunset growing zones 6-24 and is native to Texas and New Mexico. It forms a green foliage clump 2 feet tall and just as wide. Flowers are brown-purple and bloom in summer and fall. The main cultivar of this species is 'Nashville', with true purple flowers, to 2 to 3 feet tall and wide.

Caring for Muhlenbergia

Plant Muhlenbergia, or Muhly Grass, in a space in the landscape that receives full sun. Ideally, these grasses should be getting 6 to 8 hours or more sun each day. They prefer soil to be well-draining, moderately fertile, and to have a pH of between 5.5 and 7.0 (acidic to neutral). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new home. At maturity, these grasses are considered to be relatively drought-tolerant, able to get by on rainwater for much of the year with supplemental waterings during extended periods of drought. Regular waterings, however, will ensure that these grasses will maintain peak health and produce profuse shows of flowers. Water deeply once a week during the active growing season, and withhold water in wintertime.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These grasses are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. The appearance of this grass can be improved by removing any dead growth in early spring. Clumps should be cut back to 3 to 6 inches above the ground in late winter every couple of years to encourage new foliage to grow and to keep plants growing vigorously. In zones where these grasses are semi-evergreen, remove only the top half to two thirds to shape the plant each spring. Every few years, especially if these grasses are grown in a cramped border or container, they will need to be divided to ensure ongoing health. For instructions on how to successfully divide Muhlenbergia plants, see the Propagation section below.

Growing Muhlenbergia in Containers
Muhly is commonly grown in the ground, but can also be grown in containers on patios and walkways. Choose a large container that is at least a 5-gallon size to accommodate the plant's mature root ball. Ensure that the container has adequate drainage holes on the bottom to allow for excess water to flow away. Fill with a well-draining potting mix amended with organic material and perlite. Top soil with a layer of mulch to suppress weed growth, maintain consistent soil temperatures, and increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new container. At maturity, they are considered drought tolerant, but will need more water than their in-ground counterparts. As a general rule of thumb, water whenever the top two inches of soil feels dry to the touch. The appearance of these grasses can be improved by removing any dead growth in early springtime. Clumps should be cut back to 3 to 6 inches above the ground in late winter every couple of years to encourage new foliage to grow and to keep plants growing vigorously. In zones where these grasses are semi-evergreen, remove only the top half to two thirds to shape the plant each spring. Every few years these grasses will need to be divided to ensure ongoing health. For instructions on how to successfully divide Muhlenbergia, see the Propagation section below.

Harvesting Muhlenbergia
In addition to being wispy additions to landscapes, these grasses are also cultivated for their cut flowers, which are used in both fresh and dried arrangements. They add airy texture and height, and are typically harvested in mid summer to early fall. Foliage color becomes most vibrant at this time of the year. To ensure color retention, make sure to harvest them before they start to lose their color. Use a sharp, clean pair of pruning shears or snips to avoid damaging stems and prevent the spread of disease. Cut at the base of stems, and immediately drop them into a bucket of cool water. Fresh stems have a vase life of about two weeks. To dry stems, bunch them and hang them upside down in a cool, dark, dry area after harvesting. Once completely dried, handle with care to avoid breaking the brittle stems. They can be added to long-lasting dry bouquets, wreaths, or used in other floral crafts.

Propagation

Muhlenbergia, or Muhly Grass, is propagated through division or seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the division method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant, especially if you are propagating a hybrid cultivar. To propagate your Muhly, follow the instructions below:

Propagating Muhlenbergia by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, and a spray bottle. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest seeds in late fall. The seed heads on plants are pretty easy to spot, they're left behind after flowers have faded, and are typically held above the foliage on thin stems. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will continue to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
Get your container prepared. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 2-6 weeks from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 65 and 72 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Propagating Muhlenbergia by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in early spring or fall. To propagate by division, follow these steps:

Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the root(s). Once you have worked it up out of the ground, lay it out.
Separate the removed patch of grass into sections using a sharp, clean knife or trowel. Ensure that each division has a healthy root system and a few shoots. Any dried out areas with dead roots can be tossed in the compost.
Prepare your pot(s) or new planting site(s) with well-draining soil and compost and work it in. Water thoroughly, and then plant divisions.
Keep soil consistently moist as the newly-planted divisions establish strong root systems in their new home. Provide regular waterings, especially during dry spells.

Problems and Pests

Muhlenbergia grasses are generally resilient, but they can be susceptible to developing issues with the following pests and diseases in the landscape: