Cutty Grass / Rautahi

Botanical name:Carex geminata
Synonyms:Carex ternaria var. gracilis, Carex confusa
Common name(s): Cutty grass, Rautahi

About:
A robust wetland sedge forming dense spreading colonies of sharply edged foliage. Easily recognised by its pendulous worm-like flower spikes and vigorous rhizomatous growth habit.

Natural habitat:
Freshwater wetlands, swamps, riverbanks, lake margins, damp seepages and forest clearings.

Growing environment:
Thrives in permanently damp to wet soils and tolerates a wide range of moisture conditions. Performs best in full sun and fertile wetland environments.

Endemic distribution:
Endemic to New Zealand and found throughout the North, South and Stewart Islands.

Height:
0.5–1.2 m tall

Width:
Spreading extensively by rhizomes

Flowering:
September – December

Fruiting:
October – March

Uses:

• Wetland restoration
• Riparian planting
• Streambank stabilisation
• Erosion control
• Farm wetland planting
• Nitrogen runoff reduction
• Rural planting
• Wildlife habitat

Appearance:
A bright to yellow-green sedge with broad sharply edged leaves arising from creeping rhizomes. Flower spikes are pendulous, narrow and often twisted, giving a distinctive worm-like appearance.

Ecology:
An important wetland species providing habitat and stabilising saturated soils. Nuts enclosed within inflated utricles are dispersed by wind and granivory.

Associated habitats:
Wetlands, seepages, pond margins, swamps, riparian margins, lowland forest clearings and freshwater ecosystems.

How to grow:
Easy to grow from seed or division. Tolerates most soils and moisture regimes but performs best in full sun with permanently moist ground. Can form extensive colonies where conditions suit.

Propagation:
Readily propagated from fresh seed and division of established clumps.

Cultural use:
Known traditionally as rautahi and associated with indigenous freshwater wetland ecosystems throughout New Zealand.

Garden value:
An excellent vigorous native sedge for wetland and riparian plantings. Its lush foliage and distinctive drooping seed heads provide strong texture and movement in larger landscape settings.