Soft rush

Soft rush, the main weedy species, is widespread and forms tussocks that extend by means of the short creeping rhizomes from which new shoots and ultimately new plants arise. Undisturbed plants grow into clumps over 1 m tall but mowing or heavy trampling alters this to a uniform spread of shoots. It is native in marshes, ditches, bogs, wet meadows, damp woods and by water, mostly on acid soils. Soft rush is abundant throughout the British Isles and is ubiquitous in moist situations and regions of high humidity. It prefers an open situation but can grow in partial shade. At one time, the soft rush and the compact rush were treated as a single species.

Soft rush flowers from June to July in the south and July to August in the north. The flowers are wind or more rarely insect pollinated. Capsules contain an average of 82 seeds and a plant may produce 700,000 or more seeds. The seeds are not ready to germinate until the April after shedding. Light and moisture are required for germination. Initially, seedlings are susceptible to drying-out, shading and mechanical damage but once established they become more resistant. The rhizomes that develop form a dense horizontal mat 6 to 50 mm below the soil surface. Stout roots penetrate vertically downwards to 25 cm. Shoots commence vigorous growth in March.