Juncus inflexus aka Hard Rush

Juncus inflexus is known as hard rush or blue rush. It belongs to the rush family, Juncaceae. This perennial grows wild in Europe, Asia and North Africa. It is native to Britain and Ireland. It also grows as an introduced plant in northeastern North America. Its wild sites include marshes, wet meadows and ditches. It grows along lakes and rivers, and on wet slopes.

The plant forms dense clumps of upright, round stems. These blue-green stems have a dull, powdery coat. Most stems lack leaves, though narrow green leaves grow at the base. Sources give garden heights from 1–3.3 feet [0.3–1 metre]. Some plants reach about 3.3 feet [1 metre]. Reported spreads range from 1–3.3 feet [0.3–1 metre]. Creeping rhizomes let the clump spread over time. Plants may take a while to settle in. Once growing well, they have a moderate growth rate. The foliage can stay green through mild winters. Cold weather may kill it back before spring growth starts.

Small flowers grow in loose cymes near the stem tips. They bloom from late spring into midsummer, with June–July given by Missouri Botanical Garden. Flower shades include straw, reddish brown and yellowish green. Brown capsules follow the flowers, each with a short beak. The stems and clump shape provide much of the garden interest. Seeds can sprout freely where conditions suit the plant.

Hard rush grows best in full sun but accepts some shade. Keep its soil moist; it also grows in wet ground. It can stand in water about 0.25 feet [0.08 metre] deep. Heavy soil suits it, including clay, though other soil types work. Neutral to alkaline soil suits it well. The RHS also reports growth in acid soil. Published USDA ranges span zones 4–9, while the RHS rates it H7. Use it beside ponds, in bog beds or rain gardens. It also suits containers when the soil stays moist. Waterside plantings can help limit soil loss.

Hard rush needs little upkeep and has few major pest or disease problems. Divide clumps in spring, or sow seed in spring. Trim old growth when needed; routine pruning is not required. People use the stems for baskets, mats and thatch. Plants For A Future lists no known food or medicinal uses. It reports mammal poisoning, including gut upset and severe nervous system effects. Do not treat this rush as an edible plant.