1 named cultivar

‘Shara’Shara Lomandra

grass

River Mat-rush

Lomandra fluviatilis

The Story

Plant Bio

Lomandra fluviatilis, commonly known as river mat-rush, is an evergreen, tufted perennial herb native to watercourses and sandy creek beds of New South Wales. The species forms dense, fine-textured clumps of narrow, arching blue-grey to grey-green leaves that feature distinctive two- or three-toothed tips.

This species is distinguished by its exceptional tolerance to Phytophthora root rot and its soft, child-safe foliage that lacks the sharp, skin-irritating margins of other mat-rushes. In spring, it produces small, fragrant yellow flowers nestled among reddish-brown bracts on branched male or unbranched female inflorescences.

Uses & Benefits:

Provides a soft, fine-textured, arching green or blue-grey accent that softens hardscapes and retains its form year-round.

Excellent for stabilising soil on slopes or creek banks, and highly resistant to Phytophthora dieback in humid climates.

Provides essential pollen and nectar for native bees, while offering shelter and foraging ground for small lizards and insectivorous birds.

Essentials

At a Glance

Plant Type

Grass

Height

30 inches

Width

20 inches

Light

Full Sun, Partial Sun

Zones

9, 10

Water

Low to Moderate

Humidity

High

Lifespan

Perennial

Native To

New South Wales, Australia

Toxicity

Non-toxic

Planting

How to Grow

Select a planting site in full sun to partial shade with well-drained to heavy clay soil.
Dig a hole twice the width of the root ball, ensuring the plant sits slightly elevated to prevent water pooling around the crown.
Backfill the hole with native soil, firming gently around the base without burying the stem junctions.
Water thoroughly to settle the soil and apply a light layer of mulch, keeping it clear of the plant's crown.

Pro Tip

Amateurs frequently weaken clumps by shearing them annually or burying the crown too deeply; professionals plant the crown slightly elevated above the soil line and only cut the foliage back every three to five years.

Keep It Thriving

Care Guide

Do

Plant the crown slightly elevated above the surrounding soil level to prevent collar rot.
Water regularly during the first summer to establish a deep, resilient root system.
Apply a low-rate, slow-release native fertiliser in spring if growth appears sluggish.

Don't

Do not prune the foliage annually or shear the plant flat like exotic turf grass.
Do not bury the crown of the plant under deep layers of mulch or soil.
Do not plant in permanently waterlogged or boggy positions.

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Fertilize
Mulch
Pest Check
Plant
Prune

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Mass PlantingErosion ControlRain GardenBorder EdgingRock Garden

Companion Plants

Dianella caerulea Callistemon citrinus Anigozanthos flavidus

Multiply

Propagation Methods

Good to Know

Common Questions

River Mat-rush questions

What zones can River Mat-rush grow in?

River Mat-rush is hardy in USDA Zones 9–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

When does River Mat-rush bloom?

River Mat-rush typically blooms in spring through summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does River Mat-rush need full sun?

River Mat-rush does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.

Is River Mat-rush drought tolerant?

Yes — once established (usually after the first full season), River Mat-rush handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.