Common Rush Juncus usitatus

Common rush forms a dense upright tussock of fine rounded green stems, and it carries no flat leaves at all, which is the quickest way to tell it from anything strappy. The brown flower cluster appears to burst out of the side of the stem partway up rather than sitting on the tip, another useful field check. Native to eastern Australia, it sits on most water sensitive urban design plant lists, and it is bought for bioretention basins, swale batters, dam edges and creek revegetation in bulk quantities.

Wet, then dry, then wet again

What earns it a place on those schedules is tolerance of both ends of the range. It will stand in water for long spells, then dry out hard between rain events and keep going, which is exactly the cycle a basin plant has to survive. Grow it in full sun to part shade, in clay, loam or engineered filter media, and keep the water up through the first summer while the roots take hold. Away from a basin that catches runoff, in a pond surround or a garden bed, keep the moisture up through summer as well, because a tussock that dries out repeatedly browns off at the base and thins from the middle. Planting rates in basins and swales are commonly six to eight per square metre, closer where erosion control matters and the cover has to close fast. The failure mode is not death, it is spread. This rush seeds itself freely, and seedlings appear wherever the ground stays damp. In a basin or along a dam edge that is precisely what you want, and the colonising is doing the revegetation work for you. In a formal garden bed beside a leaking tap it becomes a recurring weeding job, so keep it to the wet and rough parts of a site and use something clumping where a plant needs to stay put.

Rush, sedge or mat rush

On a wet site the other candidate is Carex appressa, which has flat arching leaves with a cutting edge and a heavier fibrous root plate for holding a bank, and which does not self seed nearly as freely. Use carex where the planting has to look deliberate and hold soil, and juncus where you want the fine vertical texture of a natural wetland and are happy for it to colonise the damp ground around it. Above the waterline on a damp batter, Lomandra hystrix is the better choice, with broader softer strap leaves, more presence in a garden setting and far more tolerance of dry spells.

Cutting back and feeding

Old stems accumulate and go tan at the base. Cut the whole tussock back hard in late winter every second or third year, before new growth moves, and it comes away clean and thickens up again by spring. On revegetation sites a slasher or brushcutter over the planting does the same job in bulk, and is worth timing before the seed sets if spread is a concern. Feeding is rarely needed, since this is a plant selected for poor and disturbed ground, but a light slow release application in the first spring after planting helps a basin close over faster. More in low maintenance.

Choosing a size

This plant is available in 3 sizes, from 68mm up to 175mm, priced from $16.95 to $32.95 per plant. The size shown is the pot the plant arrives in, which is the rootball, not the height of the plant. These are younger plants, priced for planting in quantity, and they establish quickly once in the ground. Not sure which to choose? Read our guide to low water gardens.