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Calamagrostis arenaria

European marram grass

Poaceae Coastal Europe and North Africa

Drought Tolerant

SunFull Sun

WaterVery Low · drought-tolerant

HardinessZones 5–9

Overview

Calamagrostis arenaria is a perennial grass growing 24-47 inches (60-120 cm) tall, forming dense tussocks that spread widely through tough, creeping rhizomes. The grey-green leaves are stiff and inrolled, 12-24 inches (30-60 cm) long, with a sharply pointed tip and a ridged inner surface; the inrolling reduces water loss in dry, windy conditions. From early summer it produces a dense, spike-like panicle 6-12 inches (15-30 cm) long, pale straw to buff, narrowing to a point. The deep, branching root and rhizome system binds shifting sand and lets the plant grow up through accumulating dunes, sending out new shoots as it is buried. It tolerates salt spray, wind, and burial but grows poorly once sand stops accumulating around it. Tussocks spread outward over years to form extensive colonies on mobile dunes. Foliage stays grey-green through the year in mild coastal climates.

Native Range

Native to the Atlantic and western Mediterranean coasts of Europe and North Africa, from Scandinavia south to the Mediterranean. Grows on mobile and semi-fixed coastal sand dunes. It has been planted and has naturalised on the Pacific coast of North America, in Australia, and in New Zealand, where it spreads across dune systems and is treated as an invasive weed.

Suggested Uses

Grown chiefly for sand-dune stabilisation and coastal restoration, where its rhizomes bind shifting sand. Planted occasionally in coastal and gravel gardens for its grey-green foliage and tolerance of wind and salt. Its spreading rhizomes and weed status limit planting near natural dune systems outside its native range.

How to Identify

Identified by stiff, grey-green, inrolled leaves with sharp points and dense, spike-like straw-coloured panicles 6-12 inches (15-30 cm) long, growing on coastal sand. It forms tall tussocks linked by tough creeping rhizomes. The inrolled leaves and dune habitat separate it from softer-leaved inland grasses.

Appearance

Size & Dimensions

Height2' - 3'11"

Width/Spread1'6" - 3'

Colors

Flower Colors

brown

Foliage Colors

green

Bloom Information

Bloom Period

~6 weeks

Summer

Spike-like panicles appear from June to August, with peak flowering in July. The wind-pollinated heads shed pollen over two to three weeks and ripen to buff by late summer. The dried panicles persist on the stems into autumn.

Detailed Descriptions

Flower Description

straw to buff

Foliage Description

grey-green

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-12 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 Range6.0 - 8.0(Neutral)

357912

Soil Types

sand

Drainagewell drained

Water & Climate

Water Needs

Very Low

Frost Tolerance

hardy

Time to Maturity

2-3 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Grows in full sun on free-draining coastal sand and tolerates salt spray, wind, and burial by drifting sand. Established plants withstand drought through deep roots and need no watering in coastal conditions. It is grown from seed or by planting rhizome divisions into bare sand, chiefly to stabilise dunes. It grows strongly while sand accumulates around the crown but loses vigour and thins once the dune becomes fixed and stable. Outside its native range it spreads across dune systems and is managed as an invasive weed. Few pests or diseases affect it.

Pruning

No routine pruning is required. Dead foliage and old flower stems can be cut back in late winter before new growth begins. Clumps can be lifted and divided in spring to propagate or to plant for dune stabilisation.