Common Rush

Credit: By Richard Hebda

Common rush is an erect, tussock-forming perennial herb of the rush family (Juncaceae). Several to many green knitting needles stand stiffly from a dense mass of old shoots and root crowns. Tough short rhizomes extend the colony outwards. The root and crown mass can be very firm, difficult to dig through and impossible to pull. Stem bases are reddish to dark brown.

The round green stems are leafless and finely grooved, extending to a sharp yellow point at the tip. Typically they grow from 25 to 130 cm (10 in. to 4 1⁄2 ft.) tall, mostly standing smartly at attention, though taller ones sometimes arch in a pleasing manner. The stems are a bit brittle but fibrous within, hence they snap easily but do not break.

A flower cluster of many branches erupts from one side of the stem a few centimetres back from the tip. Small (2.5 to 4 mm long) inconspicuous flowers terminate each branch. Like sedges and grasses, rush flowers have no showy parts; however, all the components of the flower are there. Three pointed sepals cup three petals forming the greenish to brownish perianth, and at its centre sit three stamens and a three-parted pistil. When fresh, the flower mass tends toward bronze-green, but turns pale brown with age.

Common rush grows widely throughout British Columbia, especially on the coast and in the southern parts of the province. Curiously it is missing in much of the interior, though populations occur in the extreme north. Beyond our province, common rush occurs widely in North America, ranging from Alaska to Mexico and eastward to Newfoundland, and in Europe and eastern Asia as well. Moist habitats are its favourite haunt, from coastal marshes and peat bogs to mountain meadows and ridges. It is especially fond of roadside ditches, dugout surfaces, damp pastures and small moist hollows.

Comox and Haida basket makers used the stems of common rush with other weaving materials. Shoots were sometimes combined with other fibre plants in plaiting cord or rope. In its less brittle stages later in the season, it serves as a natural quick-tie in the garden. As an indicator of a seasonally moist situation, it is of value in assessing the conditions of a site. Many housing development tracts are cleared of natural vegetation before you see them. Common rush is an early colonist and clearly indicates high winter water tables or seepage sites. It often colonizes the hollows that form at the point where a slope failure may be about to happen. Halfway up the sloping pasture on our property, numerous clumps of this plant signal that the hard-packed summer soil turns wet, seepy and squishy in the winter, a less than ideal building spot.

Common rush is best used in the moist garden, especially at the edge of a pond. The tussock form is visually pleasing. Its dense clumps provide excellent structural strength, resisting erosion well and clearly defining the pond edge. A fascinating form with spiralling stems, commonly known as corkscrew rush (‘Spiralis’ or ‘Unicorn’), is widely available in garden centres and nurseries. Common rush is easily grown from rooted segments of tussock and seed. Clumps can also be used as accents in formal beds, but be prepared for control measures because new plants pop up readily from seed.

Using plants to enhance the quality of your property is a wise real-estate strategy. Common rush not only provides a fine native subject for moist sites but is also a tool for assessing the characteristics of a site for building.

The following plants are hardy to the zone number indicated:
Juncus effusus (common rush) – zone 3 • Juncus effusus ‘Spiralis’ (corkscrew rush) – zone 4 • Juncus effusus ‘Unicorn’ (corkscrew rush) – zone 4

An expert on native plants, Richard Hebda is curator of Botany and Earth History at the Royal British Columbia Museum in Victoria.

PHOTOS Richard Hebda: common rush; courtesy Heritage Perennials Juncus effusus ‘Spiralis’