Phragmites australis

Phragmites australis (08/09/2012, Kew Gardens, London)

Position: Full sun

Soil: Moist, wet soil

Flowering period: Summer

Eventual Height: 4m

Eventual Spread: 4m

Hardiness: 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b

Family: Poaceae

Phragmites australis is a perennial grass with a tufted habit. Its erect culms bear overlapping sheaths of linear, green/ glaucus leaves which become light brown in autumn. In late summer its inflorescence takes the form of terminal dark purple flowering panicles, densely composed from spikelets. It spreads by underground runners which put down roots and where conditions are suitable it may spread up to 5m per year.

Phragmites australis Flower (08/09/2012, Kew Gardens, London)

Phragmites australis, commonly known as the Common Reed, is a cosmopolitan species ranging across the globe although there is discussion on the topic of separating it into distinct species based on genetic evidence. The plant is currently widely used in the remediation of sewage water and various types of grey water through the use of constructed wetlands. This plant will grow in freely drained soil to water to a depth of 1m. Phragmites australis subsp. australis is a problem wetland species in North America and the native Phragmites australis subsp. americanus should be specified in this location. For more information on this pant and its identification please see the Phragmites Field Guide.

Phragmites is derived from the Greek phragma, meaning a ‘fence’ or ‘screen’, with australis being a Latinised word meaning ‘of or from Australia’.

The landscape architect may find Phragmites australis useful for both terrestrial and water planting, and especially when used in the remediation of spoiled water in the form of formal or informal water treatment beds. Careful consideratyion should be given when specifying this plant and locating this plant as it is potentialy invasive when planted near damp grassland when not grazed by cattle. In waterbodies Phragmites australis can be grown in large containers to restrict its growth and spread. This plant associates well with river edges, wildflower meadows and wildlife landscapes.

Phragmites australis (05/05/2012, Kew Gardens, London)

Phragmites australis will tolerate almost any soil conditions; it will be happy at neutral, alkaline or acid pH levels, in loam, clay, chalk or sand based soils, in a west or south facing, sheltered or exposed aspect.

Ecologically, Phragmites australis will attract various species of birds that will use it as cover from predators.

Phragmites australis requires little to no maintenance. It may be cut back to ground level in late autumn or winter.