Juncus patens is a striking vertical accent to be used anytime you have an area that gets more water than the rest of your yard. It works well in swales, and is in fact one of the few (like Carex) to survive on the bottom of the swale where it gets inundated with water during the rainy season. In my yard it stays small since there’s not a lot of light in the swale, but I’ve seen it grown in Van Nuys in full blasting sun and lower amounts of water and it gets to be a 3 foot wide by 3 foot tall clump that I greatly enjoy. Grow it with water early on in its life and then taper it off to a minimal to moderate amount and you’ll have yourself a striking accent plant.

There are many cultivars of Juncus, and genuinely, I have trouble telling them all apart.

Calscape