Thamnochortus spp.

thatching reeds

Restionaceae

Cape Floristic Region of South Africa

Deer Resistant Drought Tolerant Container Friendly

SunFull Sun

WaterLow · drought-tolerant

HardinessZones 9–11

Overview

Thamnochortus spp. is a genus of about 33 species of evergreen, reed-like perennials in the family Restionaceae, the restios or Cape reeds, almost all endemic to the Cape Floristic Region of South Africa. Like other restios, the plants have green, photosynthetic stems and lack true leaves, which are reduced to dry, papery sheaths along the wiry culms. Clumps range from about 1.5 to 6.5 ft (0.45 to 2 m) tall depending on species, forming dense, fountain-like tufts. Plants are dioecious, with separate male and female individuals, and are wind-pollinated; the flowering spikelets form plumes in shades of brown to golden that hang or arch from the upper stems. T. insignis, the thatching reed, is harvested commercially for roof thatch in the Western Cape. The genus grows in nutrient-poor, sandy fynbos soils and is adapted to a Mediterranean climate of wet winters and dry summers; most species decline in rich soil, with summer water, or after root disturbance. Plants are frost-tender to lightly frost-hardy and short-lived where conditions do not suit them.

Native Range

Native to South Africa, almost entirely within the Cape Floristic Region of the Western and Eastern Cape, where the species grow in fynbos vegetation on sandy soils. T. insignis occurs in the southern Cape.

Suggested Uses

Grown as evergreen accent and structural plants in water-wise, coastal, and Mediterranean-climate gardens, in gravel and fynbos-style plantings, and in large containers, spaced 2-4 ft (0.6-1.2 m) apart. T. insignis is also grown and harvested as a thatching material.

How to Identify

Identify Thamnochortus spp. by dense tufts of slender, wiry green stems that carry out photosynthesis in place of leaves, with leaves reduced to thin brown sheaths. Male and female plants differ, and the wind-pollinated spikelets gather into brown to golden plumes on the upper stems, often arching outward. The fountain-like clump of leafless green culms separates restios from true grasses and sedges.

Appearance

Size & Dimensions

Height1'6" - 6'6"

Width/Spread2' - 4'

Colors

Flower Colors

brown

Foliage Colors

green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~6 weeks

Spring Summer

Flowering occurs mainly from spring into summer, with timing varying by species and locality. The small wind-pollinated flowers are grouped into brown to golden spikelets that form arching plumes, holding their colour for several weeks. Female plants ripen small dry fruits after flowering.

Detailed Descriptions

Flower Description

brown to golden

Foliage Description

green culms with brown sheaths

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-10 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range4.5 - 6.5(Acidic)

357912

Soil Types

sand rocky

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

2-4 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Across the genus, Thamnochortus spp. grows in full sun in sandy, sharply drained, nutrient-poor, acidic soil with a pH of about 4.5 to 6.5. Plants are adapted to a winter-rainfall climate and tolerate summer drought once established, declining with rich soil, fertilizer, or summer overwatering. Most species are frost-tender to lightly frost-hardy and suit USDA zones 9-11. Young plants establish slowly and are sensitive to root disturbance, so they are planted out while small. Good airflow reduces fungal problems in humid climates. Established clumps are long-lived in suitable fynbos-like conditions.

Pruning

Little pruning is needed. Old flowering stems and any dead culms are cut out at the base after they fade, keeping the clump fresh. Plants do not regrow well from cuts into the green culms, so shearing the whole tuft is avoided.