Tassel Cord Rush Baloskion tetraphyllum

Tassel cord rush, still sold in many nurseries under its old name Restio tetraphyllus, throws up slender upright culms topped with soft feathery whorls of bright green, so an established clump reads as green mist rather than as a strappy tuft. It spreads by short rhizomes, steadily rather than aggressively, building a widening stand. It is planted where ground stays damp: pond and creek margins, the low point of a swale, rain gardens, and large courtyard pots standing in a saucer.

Ground that stays damp

This is a plant of eastern Australian swamps and creek edges, found from Queensland through New South Wales and Victoria to Tasmania, so it is at home in temperate and subtropical gardens and takes frost and coastal exposure without trouble. Soil should hold moisture: heavy loam, clay that stays damp, the boggy end of a bed, or a pond edge where the crown sits above the waterline and the roots reach down into it. Sandy soil works if it has been improved with compost and does not dry out. In a pot, use a mix that holds moisture and stand it in a saucer. Give a clump room to widen instead of boxing it in against a path. Coastal gardens suit it, and it will take a position at a pond edge that gets splashed or occasionally inundated.

The failure mode is a bed that dries out hard. Planted in a dry exposed position, the culms brown off from the base, the clump thins, and recovery is slow even once conditions improve, because it rebuilds from the rhizome rather than reshooting along the old culms. Match it to genuinely damp ground and this does not happen.

Plume rush beside the mat rush

Dalliance mat rush is the plant most often cross shopped with this one, and the difference is the site. Mat rush is the tough all rounder, coping with a dry batter, a hot carpark strip and a swale that floods now and then. Tassel cord rush is a specialist for the wet end of that range and it looks completely different, fine and feathery instead of arching and strappy. Use cord rush at the water and mat rush on the slope above it. Where a wet site is big enough for a tree as well, swamp she-oak is the canopy layer for the same ground. More in the native range.

Cutting out old culms

Do not shear the top of a clump. Cutting the culms partway leaves blunt ends that stay visible for a year and wrecks the feathery outline that you bought it for. Instead, cut tired or browned culms right out at the base with secateurs, a few at a time, at any point through the growing season, and let new culms come up from the rhizome to replace them. Divide congested clumps in spring, keeping rhizome and roots on every piece. Feed lightly with a low phosphorus native fertiliser in early spring, and mulch around the base to hold moisture in.

Choosing a size

This plant is supplied in one size, 140mm, at $16.95 per plant. The size shown is the pot it arrives in, which is the rootball, not the height of the plant. Not sure which to choose? Read our guide to Australian native trees.