Posted by Brent Wilson on 10/7/2016 to Fertilizing & Watering Tips
When planted right and in the right spot, Muhly grass, which some call "cotton candy grass," is exceptionally easy to grow and care for.
In landscape design, Muhly grasses are useful as specimens, groupings or mass plantings, as a hedge or border, or make nice additions to container gardens. They provide fine texture season long and outstanding blower color in the late summer to fall landscape.
Here's a breakdown of what you need to know for how to plant and care for Muhly grasses...
Muhly grass is easy to grow in a wide range of soils. They prefer a moist but well-drained soil while establishing themselves, however are exceptionally tolerant of dry soil when established. As with so many other ornamental plants, constantly soggy or wet soils can be problematic.
How To Test Soil Drainage
If you are uncertain about soil drainage in the area you intend to plant your Muhly grass, it's well worth taking the time to test the drainage before planting. To test soil drainage, dig a hole 12" wide by 12" deep in the planting area. Fill the hole with water and let it drain. Then, after it drains, fill it with water again, but this time clock how long it takes to drain. In well-drained soil the water level will go down at a rate of about 1 inch an hour. A faster rate, such as in loose, sandy soil, may signal potentially dry site conditions and the need to provide supplemental water until new plants are established. A slower rate indicates poor draining soil and could be a caution to improve drainage if possible or to look for plants that are more tolerant of boggy conditions.
Muhly grass thrives in an acid to neutral soil ranging from 5.5 to 7.0 on the pH scale. Most average garden soils fall between a pH range of 6.0 to 7.0..
Testing Soil pH
Soil pH is a measurement of the alkalinity or acidity of soil and is measured on a scale of 1-14, with 7 as the neutral mark. Any measurement below 7 indicates acid soil conditions, and anything above 7 indicates alkaline.
If you're unsure about the pH of your soil, or not sure if your soil is suitable for growing Muhly grass, it's a good idea to test the pH in the planting area. You can quickly test soil pH with an inexpensive soil pH tester probe. To raise the pH (make more alkaline) you can add pelletized limestone to the soil. To lower the pH (make more acid) you can apply Soil Sulfur, Aluminum Sulfate, or Chelated Iron. Adding organic compost to the soil or using compost as mulch can also help to increase acidity and maintain acid soil conditions.
Learn More: What is Soil pH and How To Adjust It?
Muhly grass prefers full to mostly sun. A little shade or filtered sun is okay. Too much shade and plants will become floppy with fewer flowers. At least 6 to 7 hours of direct sun per day is recommended.
Planting Muhly Grass In The Ground
(Scroll down to see planting instructions for containers and pots)
Start by digging your planting hole two to three times as wide and not much deeper than the root ball of your plant. The wider the hole the better. Place native soil removed from planting hole around the perimeter of the hole, in a wheel barrow, or on a tarp.
Depending on the type and porosity of the soil in the planting area it might be beneficial to amend the native soil. Muhly grass prefers a very well-drained soil. Constantly soggy or wet soil is a killer. When planting in dense clay, or other poorly drained soils, it is beneficial to thoroughly mix in some bagged top soil, sand, and/or small gravel at a 50/50 ratio with the clay soil to improve drainage. When planting in very sandy, quick-draining soil you might want to consider mixing in a little top soil to help retain some moisture.
Tip: Before removing the rootball of your plant from the nursery pot it was grown in give it a good deep soaking with water from the garden hose.
To remove your Muhly grass plant from the container it was growing in try to gently lift and remove it from its container. If the root ball is stuck in the container either cut the container away or place the plant on it's side and tap on the side of the container to loosen the root ball. After having removed the plant from the container, loosen some feeder roots around the surface of the root ball.
Set your Muhly grass in the planting hole so that the top edge of the root ball is at or slightly above ground level to allow for settling. It may be necessary to place some of your backfill soil mixture in the bottom of the hole to achieve proper planting height.
Note: If the soil is poorly drained (stays constantly soggy or wet) improve drainage or choose another plant species tolerant of wet soils.
After setting your Muhly grass in the planting hole, use one hand to hold it straight while using your other hand to begin backfilling the soil mixture around the root ball, tamping as you go to remove air pockets. When you have filled the hole to the halfway point you can soak the soil. Then continue backfilling to the top edge of the root ball. To avoid suffocating your plant, avoid placing any soil on top of the root ball.
Step 6 (Optional)
If you are planting your Muhly grass in a location far away from a water source in very well-drained soil, you can use remaining soil mixture to build a water retaining berm (catch basin / doughnut) 1 to 2 inches in height around the outside perimeter of the planting hole. This basin will help to collect water from rainfall and irrigation often reducing the need for hand-watering. The berm can be removed after a growing season.
Next, deeply water the planting area, including the root ball, to a depth equal to the height of the root ball.
Apply a 1" layer of cured, shredded wood mulch or bark, or a 2" layer of pine straw, around your newly planted Muhly grass. Avoid the use of freshly chipped or shredded wood for mulch until it has cured in a pile for at least 6 months, a year is better.
Planting Muhly Grass In A Container
Muhly grass growing in pots appreciate a moist but well-drained soil. Constantly soggy or wet soil can and often will cause root rot or other harmful plant diseases. Therefore, I recommend a pot with a drainage hole(s) filled with a high quality potting soil or professional potting mix, or a 50/50 combination thereof. To enhance drainage, pumice or perlite can be added at a 20% ratio the the soil.
Choose a container that is large enough to allow for 2 to 3 years of growth before shifting up to a larger size container. This might mean your planting pot would be 6 inches or more in width than the root ball of your plant.
Container color will matter as well. Not only will you want to pick a color of container that goes well with the foliage color and texture of your Muhly grass, you'll also want to pick a container that matches the style of your home or other structures and other plants in the surrounding environment.
Many nursery & garden centers offer a wide variety of containers to choose from. Before heading out to buy a container take pictures of your home and the surrounding environment. Doing so will help you to choose just the right color and style.
Before filling your container with the soil mix, we recommend lining the bottom with shade cloth or a porous landscape fabric. This will keep the drain holes from becoming stopped up with soil. If you use gravel, rocks, bricks or other materials in the bottom of the container lay the fabric on top.
To remove your Muhly grass plant from the container it was growing in, firmly grasp the base of the plant and try to gently lift and remove it from its container. If the root ball is stuck in the container either cut the container away or place the plant on it's side and tap on the side of the container to loosen the root ball. After having removed the plant from the container, loosen some feeder roots around the surface of the root ball.
Pour a small amount of your soil mixture in the bottom of the container. Set the plant in the container and make necessary adjustments by adding or removing some soil so that the top edge of the root ball will sit 1" or so below the rim of the container.
Backfill with your potting soil around root ball, tamping as you go, until the level of potting soil is even with the top edge of root ball.
Water thoroughly until water starts to drain from the holes in the bottom of the container. Add more potting mix if settling occurs during watering.
Step 6 (Optional)
Apply a 1/2" layer of wood chips or sphagnum moss to soil surface. You might also consider adding low spreading annual or perennial flowers or groundcover plants as soil cover and/or spiller plants around your Muhly grass.
Muhly Grass Care Tips
Feeding - Watering - Pruning
Muhly Grass are exceptionally easy to grow and care for. Below are some helpful care tips that will have you growing them like the pros.
How To Fertilize Muhly Grass
Muhly Grass does not require fertilizer. That being said, if your plants don't show vigorous growth they can be fertilized lightly in late winter or early spring with a mild organic plant food.
How To Water Muhly Grass
At Planting Time
Immediately after planting deep soak the soil in the planting area to a depth equal to the height of the plants root ball. When planted during the winter dormant season Muhly grass plants will require less water. So, be extra careful not to overwater during winter!
During the First Growing Season
In average garden soil you should not have to water your newly planted Muhly grass every day. More often than not, this causes soggy soil conditions that can lead to root rot and other harmful plant diseases. In the absence of sufficient rainfall, water only as needed to keep the rootball and surrounding soil damp to moist.
Keep in mind that deep soaking less frequently, and allowing the soil to dry out somewhat before watering again, is much better than splashing just a little water on the plants every day. During the winter dormant season, when plants are not actively growing and evaporation is much slower, plants will require much less water. So, be extra careful not to overwater during winter!
When established Muhly Grass are exceptionally drought tolerant plants. Only during prolonged periods of summer drought will plants require supplemental irrigation.
Note: When watering with an automated irrigation system it's best to set your timer to water during the early morning hours and not in the late evening or at night, which can lead to the onset of fungus and other foliage diseases. During the first few weeks after planting, check soil moisture often and adjust irrigation time if necessary to keep the soil moist, not wet.
How To Prune Muhly Grass
In late winter, before new growth begins to emerge from the ground, use hedge trimmers or sharp scissors or bypass hand pruners to trim the foliage to an inch or two above the ground. If you wait too long and new green leaves have already begun to emerge, go ahead and trim the foliage back. It's better to do that than to look at straw-color foliage mixed with fresh green foliage throughout the season.
Plant Long & Prosper!™
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