FBMG 2014 Project: Ornamental Grasses

By Cheryl Huber, Fort Bend County Master Gardener

Our team set out to find which ornamental grasses and “grass-like” plants would do best in the Southeast Texas sun and summer heat using the Earth-Kind Landscaping practices, including no additional irrigation once plants were established and a thick layer of native mulch on the surface.
The project began with deeply tilled soil beside the driveway, between the Annex building and the barn. Heat was reflecting from the building and driveway, so we made sure we planted a foot from the building and a foot from the concrete. We planted rows with 3 ornamental grasses in each row. Those that grew under a foot at the front, those that grew over a foot, but expected to stay under 4 foot, in the middle, and those that grew taller in the back, toward the Annex building. We provided a drip system, until the grasses were established, showing signs of new growth.
We checked the mulch weekly, to maintain a 3 to 4 inch layer, used to contain grasses, slow down weed growth, and moderate soil moisture. Light weeding was done as needed throughout the project. The majority of the grasses were provided by sponsoring nursery partners Greenleaf Nursery in El Campo, The Color Spot in Fulshear, and Caldwell Nursery in Rosenberg. We evaluated a total of 74 plants.
Final results for this project will be published next year, but for now, this is my simplified version of the results to date.
I will begin my evaluation with the low growing varieties. I used to believe if it had Carex in the name, don’t bother planting this in full Texas sun. It likes damp soil. This proved true with Carex morrowii ‘Goldband’. It didn’t survive the second week. Conversely, Carex cherokeensis, and Carex retroflexa, proved me wrong. They survived the heat, show no negative symptoms, and are filling in well. Note: the genus Carex is not a true grass, but provides similar grass-like texture in the landscape.
Two low growing grasses caught my attention because of their beautiful seed heads. The plumes were plentiful on both of these grasses, the Melinis nerviglumis (Ruby Crystals Grass), and Pennisetum alopecuroides ‘Hameln’(Dwarf Fountain Grass).
Also not true grasses, but included in the trial, Liriope spp. (Lily Turf) did not perform so well. Liriope leaves lost their color in the hottest part of the summer and some of the leaves burned on the tips while others completely burned. Ophiopogon spp. (Mondo grass) per-formed better, but the leaves tended to brown at the tips.
In the middle row, the Pennisetum ‘Eaton Canyon’ (a Dwarf Red Fountain Grass) tried to steal the show. Andropogon Scoparius ‘Little Blue Stem’ was nearly unnoticed, until fall and the stems took on a colorful hue. Then the upright behavior of the colorful grass begged for attention. Panicum Virgatum, ‘Shenandoah’ Switchgrass deserves mention here. It has pink, dainty seed heads that wave in the wind.
The big guys on the back wall of the annex, Cymbopogon, commonly known as lemongrass, Muhlenbergia and Miscanthus all did very well. Miscanthus took longer to get going, but bounced back and has since flourished.
Phase 2 of this project will be looking at how well each of these selections over-winter (come back in spring after the cold exposure of winter). Stay tuned for more updates on this exciting project.
For more information on Earth-Kind Landscaping visit http://aggie-horticulture.tamu.edu/earthkind/.

Comments are closed.