Carex riparia aka Greater Pond Sedge

Carex riparia is a perennial sedge in the Cyperaceae family. Common names include greater pond sedge and greater bank sedge. It is native to Britain and Ireland. Its range spans Europe and reaches central Asia. RHS also lists southern South America within its native range. It grows beside slow rivers, in ditches, and around ponds. PFAF notes that it sometimes grows on drier ground too.

This plant forms tufts and spreads strongly through underground rhizomes. Garden plants reach about 3.3–4.9 feet (1–1.5 metres) tall. Their spread falls within the same range. RHS gives two to five years for plants to mature. The long, narrow leaves are green with a blue-grey cast. The foliage is deciduous, rather than green throughout the year. Tall stems carry thick, upright spikes of dark brown flowers. These appear in early summer, above the mass of leaves.

Grow this sedge in fertile soil that stays moist or wet. It accepts full sun as well as partial shade. RHS lists both clay and loam as suitable soils. Acid, neutral, and alkaline soils all fall within its range. Poor drainage suits it, making wet ground a useful planting site. Its UK hardiness rating is H5. PFAF lists it for USDA zones 5–9. These ratings describe hardiness in different systems and regions.

Its wet-ground needs suit pond edges and bog gardens. RHS also suggests wildlife gardens and wildflower meadows. Its strong spread matters when choosing a place for it. Allow room for the clump to widen through its rhizomes. RHS includes it among plants suited to low-maintenance gardens. Cut the growth back once flowering has ended. Sow seed in autumn to raise new plants. Divide established clumps from mid-spring through early summer. Aphids may attack it, but RHS reports few disease problems.

PFAF records cooked roots and seeds as edible parts. It gives the plant a low food-use rating. The seeds are small and awkward to prepare for use. Its account gives no further detail about eating them. PFAF reports no known hazards, but this does not prove universal safety. It lists no known medicinal uses for this species. The dried stems also have a recorded use as bedding.