Not to be confused with the Canadian rock band from the 1970s, this rush, Juncus patens, is native to riparian areas between western Washington and San Diego County. It is also known as the common rush because it is, obviously, the most common species of the genus on the West Coast. It is only occasionally planted intentionally, but more often sneaks into well irrigated landscapes.
Those planted intentionally are mostly cultivars with slightly bluish or grayish foliage, such as ‘Elk Blue’, ‘Occidental Blue’ and ‘Carmen’s Grey’. Those in the wild, or that sneak into landscapes from the wild, are dark green like avocado skin. The upright foliage is really very slender stems that look more like leaves than the vestigial leaves do. It forms dense clumps about one to three feet tall.
Although it is a riparian plant that survives soil saturation and inadequate drainage through winter, rush can survive as soil drains and dries somewhat through summer. It prefers somewhat regular watering in landscapes and home gardens. If cut back to the ground at the end of winter, and perhaps divided, fresh new growth regenerates through spring. Growth is sparse and floppy in shade.
Tony Tomeo 
I’d never looked at the BONAP maps for the genus, and didn’t realize how many species of rush there are. We have several natives, but this one clearly is yours, all yours, and it’s attractive. Is it my imagination, or are there little ridges on its surface?
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Yes, they are striated. It gives the seemingly grassy foliage an odd slightly coarse texture. The leaves do not slip past each other as fluidly as smoother foliage might. It gives a bit of resistance when walking through a thick colony of it.
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I love to see rushes and reeds. They seem magical to me.
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This particular one is rather simple and weedy, but the others really are like something from another planet or distant past. They look like something that dinosaurs would eat.
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yes! or that faeries would inhabit, but mostly they do look primeval.
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Faeries?! Now that sounds scary.
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Could be. I’ve heard they aren’t always agreeable.
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