Bull grass is a top-performing, but little-known, ornamental grass with a bevy of attributes. It’s a desert native that’s compact, has a long bloom season, is nearly maintenance-free, and doesn’t need to be divided.
Bull grass (Muhlenbergia emersleyi) is considered one of the most desirable native grasses for the landscape. But it might be one you’ve never heard of!
It’s less commonly used in the landscape than some of the more popular “muhly” grasses, in part because it’s harder to find at nurseries. But it definitely has some impressive attributes and may be worth seeking out.
This southwest native has soft blue-green leaves that make a nice contrast to harsh desert surroundings. It’s a compact rather than sprawling ornamental grass which readily fits in small spots in your garden.
It blooms earlier and lasts longer than many ornamental grasses, sometimes sending up the first stalks of white flowers as early as June. And it continues to bloom through November.
And perhaps my favorite feature of all is that, unlike many ornamental grasses, it doesn’t need to be divided every few years. (Digging up and dividing established grasses can be a real pain!) 🥵
Bull grass attracts wildlife. Birds eat its seeds and use the foliage to build nests and provide shelter. It is a host plant for some native species of butterflies and moths.
Muhlenbergia is genus of 175 grasses, mostly native to the desert southwest.
But only a handful are used as landscape plants.
Why I Like This Plant
- Beautiful white plumes
- Low water use and low maintenance
- Attracts birds and butterflies
- Compact for small spaces
- Long bloom period — summer through fall
- Doesn’t need to be divided
Things to Watch Out For
With all of these attributes, you may wonder why it isn’t more commonly planted.
That’s probably because it can be hard to find. Your best bet will be to check out local nurseries that specialize in native plants.
Here in Tucson, that would be Spadefoot Nursery or Desert Survivors. If you aren’t looking for instant gratification, you can start bull grass from seed. Borderlands Nursery and Seed sometimes carries them. In a pinch, you may find plants or seeds online.
Optimal Growing Conditions
If you’re thinking of adding bull grass to your garden, you need to find a suitable place that will keep your plant healthy and looking good… while minimizing maintenance for you.
Here are the key factors to keep in mind.
Temperature
Bull grass should be grown in USDA Hardiness Zones 7 – 10. As a desert native, it can handle temperature extremes. It is cold-hardy down to around 0°F and is one of the most heat tolerant of the muhly grasses.
Sun Exposure
Bull grass readily handles full sun and even reflected heat, but can also be grown in part shade.
Size and Growth Rate
Bull grass is a fast grower that reaches a size of 2 – 3′ tall by 2 – 3′ wide. It is somewhat smaller than the other muhly grasses, which need room to spread out.
Soil
Bull grass is not fussy about soil and grows in any desert soil — sandy, rocky, or clay — provided it’s well-draining.
Other Location Considerations
Because it has no thorns, is non-toxic, and produces minimal litter, it’s a plant you can feel comfortable placing near a pool or sidewalk, or anywhere it might come in contact with pets and people. (The only time it can be messy is when it’s time to prune.) The wispy inflorescences are not spiky, irritating, or toxic.
Since bull grass is smaller than many other ornamental grasses, it’s a good choice where space is limited.
Bull Grass:
The Essentials
| Common Name | Bull grass |
| Scientific Name | Muhlenbergia emersleyi |
| Origin | Southwest US, Mexico |
| Plant Type | Bunch grass |
| USDA Zones | Zones 7 – 10 |
| Cold Hardy | To 0℉ |
| Flower Color | White |
| Flower Season | Summer, fall |
| Mature Size | 2-3’ high x 2-3’ wide |
| Growth Rate | Fast |
| Sun Tolerance | Full, part, or reflected sun |
| Water Needs | Low |
| Pests & Diseases | None |
| Garden Friendly | No thorns, non-toxic, not invasive |
| Wildlife | Attracts birds, butterflies Deer resistant |
How to Plant
The rule of thumb when planting any ornamental grass is to dig a hole three times as wide as the root ball but no deeper. Amending the soil is not recommended. Counterintuitively, backfilling with the same native soil you just dug up helps your plant develop a stronger root system.
When to Plant
The best time to plant bull grass is in the fall. This gives your grass three seasons to grow roots and get established before the following summer. But you might not be able to find it in the fall. I’ve found the usual sources are sometimes out of stock.
The second best time is in spring, the earlier the better. This still gives your plant time to get established before the intense heat of June arrives.
How to Care for Bull Grass
Whether you’ve recently planted bull grass or have an existing plant in your yard, here’s how to take care of it to keep it healthy and looking its best.
How to Water New Plants
As a southwest native, bull grass needs very little water once established, but it does need regular watering after being planted.
Here is the recommended watering schedule for new ornamental grasses.
| Weeks 1 & 2 | Every 3 – 4 days |
| Weeks 3 & 4 | Every 6 – 7 days |
| Weeks 5 & 6 | Every 7 – 10 days |
| Weeks 7 & 8 | Every 10 – 14 days |
How to Water Established Plants
Once your bull grass is established, water it deeply every two weeks during the summer. If not given enough water, plants will survive but they can die back.
Since plants go dormant in the winter, they only need water once a month, which is typically provided by winter rains.
Should You Fertilize?
There is no need to fertilize bull grass since it gets all the nutrients it needs from native soil.
How to Prune
Bull grass should be pruned hard once in late winter or early spring. Cut it down to 3 – 4 inches above the ground.
You can cut it straight across, but slightly irregular cuts look more natural and mimic the grazing that would occur when growing in grasslands. This lets light penetrate the crown and makes way for new spring growth.
Pro Tip!
Tightly tie the dried leaves and flower stalks
with string or duct tape before cutting.
This makes clean-up much easier.
Bull Grass Cultivar
Muhlenbergia emersleyi ‘El Toro’ is a naturally occurring variety that grows in oak woodlands from Arizona to Texas. This landscape plant is a clone of an Arizona plant selected for its showy mauve-pink plumes. Compared to the standard form, it’s slightly more cold tolerant (down to -10℉).
If you love the look of pink grasses, ‘El Toro’ is an option to consider.
Instead of pink muhly (which needs lots of space), consider ‘El Toro.’ Not only is it a smaller grass, its pink seed stalks last much longer.
Instead of purple fountain grass, which is potentially invasive, plant ‘El Toro.’ It’s a safe but colorful alternative.
Plant Lover Facts
Bull grass (Muhlenbergia emersleyi) is also called bull muhly and is sometimes spelled as one word (bullgrass).
Its common name is probably derived from its Mexican common name, Zacate de Toro, which translates to bull grass.
The genus, Muhlenbergia, was named after the German botanist Gotthilf Muhlenberg, who is credited with classifying and naming at least 150 plant species.
Have you grown this plant?
Was it a “hit” or a “miss” in your garden?
Please share your experience in the comments below!
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Author Bio
Deane Alban is the creator of Southwest Gardener. She is a science writer with a bachelor’s degree in botany from the University of South Florida. Gardening is her lifelong passion. She’s been gardening in Tucson for 15 years.
Photo Credits
David Bygott, CC BY-SA 4.0, iNaturalist,