I have a thick, beautiful lawn that borders my garden. Unfortunately, I am struggling to keep the grass from infesting my garden. I have used a variety of herbicides, mostly RoundUp, along the garden border, but nothing I have used so far seems to have much of an effect. My only success in controlling this grass is to dig it up, but this is difficult due to the deep root system, and often requires that I uproot healthy garden plants in order to remove the grass and its roots.
I want to identify this grass, which I hope will help me learn additional ways to control it. The identifying characteristics include long root runners that look like the roots of bamboo.
Another feature is the presences of nodes in the root system, from which many large and small tendrils extend. These nodes tend to appear at depths up to 4 inches or so, but the runners tend to run rather deep in the soil, often reaching down 8 inches or more. The following image shows the root node of a small grass clump.
And here is the foliage of this same grass clump.
I will appreciate any help in identifying this intruder and some means of controlling it. I have been fighting it for several years, and am hoping that there is a tactic other than sinking a deep root barrier to keep it out.
Oh, and this is probably important information: I am located in southeast Texas, north of Galveston Bay and east of Houston.
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Both GardenerJ and alephzero appear to be correct. I accepted GardenerJ's answer as the correct one, only because he answered first. Thank you both for your answers!
Elymus repens (also known as couch grass and quackgrass, and, according to Wikipedia also as twitch, quick grass, quitch grass (also just quitch), dog grass, scutch grass, and witchgrass) is nasty and difficult to control. My whole lawn was originally planted with St. Augustinegrass, but the quackgrass also appears throughout.
I have been successful in extracting it manually, but it is never a complete job, and you have to keep after it. After extracting every bit that I can find in the garden (sometimes the rhizomes are as long as 5 feet long), I keep looking for new foliage, and dig that out as soon as possible.
I have used RoundUp along the garden perimeter, and that helps, but the rhizomes run deep and can survive the poisoning. Also, it is necessary to keep the lawn cut, in order to prevent the Elymus repens from going to seed.