Walking around the garden I was astonished by the beauty of grass that was so picturesque backlit by the sun. It was a muhly grass but not the pink cotton candy looking one you admire in the fall. This was bamboo muhly native to Arizona. You don’t normally think about plants native to Arizona being so adaptable to the hot humid southeast but bamboo muhly is like having a fine piece of art in the garden.
Botanically speaking it is Muhlenbergia dumosa, though several references claim it is native to parts of New Mexico and California, I can’t confer that with the USDA. We have several of these 6-foot tall fine textured plants that really do look like bamboo. I remember years ago Karl Foerster feather reed grass being called a perpetual motion plant in the prevailing breeze but it pales in comparison to bamboo muhly.
You may be thinking that anything called bamboo is to be feared but not this incredible clump forming grass. I assure you if the only grass you grow is the one you mow, you are missing out. This is a grass grown strictly for the wispy fine or thread-like element it provides in the landscape.
Bamboo muhly is cold hardy from zones 7-10 and will perform in full to part sun. If you think about a plant native to Arizona you know what the critical factor will be. It must have good drainage. On the onset you must provide enough water to get established and then you have a tough-as-nails landscape element.
Here at the Coastal Georgia Botanical Gardens, we are using some in partnership with large fan-leafed palms. This is the ultimate in contrasting foliage with the bold or coarse textured tropical palm and the fine textured grass moving in the breeze. In another area, we have it partnered with dwarf oleander and in another area with Soft Caress mahonia. All of these combinations stand out because of their differing leaf color and shape.
My favorite partnership in the garden is the one nearby to the Chinese Goddess bamboo. This small tight clumping bamboo is known botanically as Bambusa multiplex ‘Rivieorum.’ Ours came to the garden via Dr. Floyd McClure in1928. There is something about these two clump forming plants that mesmerizes me.
To grow bamboo muhly, choose a site in full sun with fertile, well-drained soil. Amend tight compacted clay as needed with 3-to-4 inches of organic matter like compost or humus. Till to a depth of 8 to 10 inches and incorporate 2 pounds of a slow-release 12-6-6 fertilizer per 100 square feet of bed area.
Dig the planting hole two to three times as wide as the root ball but no deeper. Plant the muhly grass at the same depth it is growing in the container, with the crown slightly above the soil profile. Know that your plant will reach 4 to 6 feet tall and as wide so allow enough space to let your plant show off its natural habit.
In Savannah, we don’t cut ours back unless the cane or stem actually dies. In colder areas, you will treat much like you do pink muhly or Lindheimer’s muhly cutting the foliage back hard to about 12 inches in late winter Apply a light application of fertilizer when pruning and again in midsummer. A little supplemental water during prolonged dry periods in the summer will pay dividends with an even more impressive show in the fall. Clumps can be divided in early spring. If I am raving about a grass in January after three days of freezing temperatures then you know this grass is something special. Jump on the grass bandwagon this spring and the US native bamboo muhly is a great place to start.