Eleocharis palustris aka Creeping Spike Rush

Eleocharis palustris is a sedge that lives for many years. It also goes by the name creeping spike rush. Its native range spans the north's temperate zone to the Himalaya. It grows wild in Britain and Ireland. It grows in marshes, wet meadows, ditches, and springs. Other sites include river edges and lake and pond shores. Some sites have brackish water, which holds some salt. This wetland plant spreads through rhizomes, which creep beneath the soil.

Smooth, round, green stems form upright tufts. RHS gives a garden height of 1.6–3.3 feet [0.5–1 metre]. Missouri Botanical Garden reports heights of up to 4 feet [1.22 metres]. Water depth affects this height. Sources give spreads of 2–4.9 feet [0.61–1.5 metres]. Stems grow alone or in groups from rhizomes. They look bare, but reddish-purple leaf sheaths wrap their bases. These true leaves have no blades. The stems thus carry out photosynthesis, using light to make food. RHS says the leaves stay green all year, or in part.

Each stem bears one small, egg-shaped spikelet at its tip. The blooms range from brown to greenish-brown and draw little notice. RHS gives May to July as the bloom time. Missouri Botanical Garden gives a later season: June to September. The plain blooms leave the upright stems as the main garden feature. It suits pond edges, bog gardens, stream banks, and rain gardens. Few grow it for show, but it suits wildlife gardens too. It copes with wet soil and helps where soil washes away.

Grow it in full sun; it also accepts part shade. RHS lists sand or loam, with neutral to alkaline soil. Keep the soil soaked, or grow it in shallow water. Once plants take root, water can reach 3 feet [0.91 metres] deep. New plugs need less depth in their first season of growth. They can live as water levels fall if soil stays soaked. Split the rhizomes or grow new plants from seed. Plants may also spread by their own seed. RHS rates it H4. Missouri Botanical Garden lists USDA zones 3–8.

It needs little care and no pruning. Serious pests and diseases are rare, though aphids may appear. Plants For A Future lists the sap as edible. It gives no more facts on its use as food. The source lists no known hazards and no uses as medicine. People have used this plant for bedding. They have also used it to fill pillows and make seat pads.