Add bold, vertical texture to wet areas with Juncus effusus (common rush). You will get dense clumps of smooth, cylindrical green stems (true leaves are reduced), creating a clean architectural accent at pond edges, rain gardens, swales, and other consistently moist sites.
Give it full sun for the strongest, most upright habit, though it will also perform in part shade. Keep the soil evenly moist to wet; it can handle very damp ground and even shallow standing water once established. In average garden beds, it will still do well as long as moisture does not dry out for long periods.
At maturity it typically reaches roughly 20-24 inches tall in garden settings, with a broad clumping spread. It can expand over time by rhizomes and may self-seed in ideal conditions, so place it where gradual spreading is welcome or contain it if you want sharper edges. Cut old stems back in late winter or early spring to refresh the clump, and divide to rejuvenate or to create new plantings. Common rush also works well in containers, especially where you can keep a saucer or reservoir consistently filled.