grass

Slender Mat Rush

Lomandra hystrix 'Katie Belles'

The Story

Plant Bio

Lomandra hystrix is a robust, evergreen perennial forming dense, clumping tufts of broad, strap-like foliage native to eastern Australian rainforest margins. The species adapts to extreme soil moisture variations, thriving in both saturated rain gardens and dry, shaded understories.

'Katie Belles' is distinguished by its highly fragrant, golden-yellow flower spikes that emerge in spring and extend well beyond the bright green foliage canopy. This cultivar maintains a highly uniform, arching habit reaching up to six feet tall and five feet wide.

Uses & Benefits:

Ornamental UsesProvides bold, arching architectural structure with bright lime-green foliage and highly fragrant golden flower spikes.
Practical UsesThrives in difficult wet-shade conditions where few other ornamental grasses can survive.
Ecological BenefitsProvides excellent soil stabilization on slopes and filters runoff in rain gardens or bioswales.

Essentials

At a Glance

Plant Type

Grass

Height

71"

Width

59"

Light

Full Sun, Partial Sun, Shade

Zones

9, 10

Water

Medium to Wet

Humidity

High

Lifespan

Perennial

Native To

Australia

Toxicity

Non-toxic

Bloom period

Spring – Summer

J
F
M
A
M
J
J
A
S
O
N
D

In flower about 6 months of the year

Planting

How to Grow

  1. Select a planting site in full sun to full shade with moist, well-draining soil or a dedicated rain garden zone.
  2. Dig a hole twice the width of the root ball and of equal depth, ensuring the crown sits level with the surrounding soil.
  3. Water thoroughly immediately after planting to settle the soil around the fleshy root system.
  4. Apply a layer of organic mulch around the base, keeping it clear of the crown to prevent moisture retention against the stems.

Pro Tip

Avoid frequent or severe shearing; cutting back into the old, brown lower stem zones below active growth points prevents regeneration.

Keep It Thriving

Care Guide

Do

  • Water regularly during the first growing season to establish a deep, drought-tolerant root system.
  • Wear thick gloves when handling or pruning to protect against the sharp, spiny tips of the flower bracts.
  • Apply a balanced, slow-release fertilizer in spring to maintain the bright lime-green foliage color.

Don't

  • Do not prune the foliage into a tight ball or cut back to the ground annually.
  • Do not plant in stagnant, completely undrained sumps where water remains pooled for weeks.
  • Do not use heavy overhead shearing tools that shred the leaf tips and leave brown, ragged edges.

Seasonal Care Calendar

TaskJanFebMarAprMayJunJulAugSepOctNovDec
Divide
Fertilize
Plant
Prune

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Rain GardenMass PlantingErosion ControlUnderstory PlantingCoastal Garden

Multiply

Propagation Methods

Good to Know

Common Questions

Slender Mat Rush questions

What zones can Slender Mat Rush grow in?

Slender 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 Slender Mat Rush bloom?

Slender 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 Slender Mat Rush need full sun?

Slender Mat Rush does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.

Is Slender Mat Rush drought tolerant?

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

Keep exploring

Explore the genus

Hardy in your zone?

Grow Slender Mat Rush with confidence

See it in a design of your actual yard, get zone-matched care reminders, and track it season by season in your garden journal.