Giant Reed, Giant Reed Grass
Arundo donax

Family: Poaceae or Gramineae

What it is like

Arundo donax is a tall, perennial grass species with edible, medicinal and other uses. It is one of the most promising crops for energy production in the Mediterranean climate of Europe and Africa. Bloom Color: Green, Purple. Main Bloom Time: Early fall, Late fall, Mid fall. Form: Upright or erect. Common Names: bamboo reed; giant cane; spanish reed; wild cane. Spanish: caña común; caña de Castilla; carizo; carrizo. French: canne de Provence; grand roseau. Arabic: ghab; qalam. Chinese: lu zhu. Portuguese: cana palustre; canno de reino. Australia: bamboo; Danubian reed; e-grass; elephant grass; giant Danube grass; oboe reed. Brazil: cana do brejo; cana do reino; cana-brava; canno do reino; capim plumoso; taquara-do-reino. Chile: cañamo. Colombia: caña brava. Costa Rica: caña hueca. Cuba: caña de Castilla; caña de río; caña hueca; cañita de la india. Dominican Republic: cañita. Fiji: ngasau ni vavalangi. Germany: Pfahlrohr. Haiti: herbe roseau; roseau. India: nal. Italy: canna commune; canna comune; canna di Provenza. Netherlands: Pijlriet. Puerto Rico: caña gigante; guajana. Samoa: fiso palagi. South Africa: Spaanse-riet. Spain: falso bamboo; gallipato alcublano; junco gigante. Tonga: kaho; kaho folalahi. Uruguay: caña musical.

Arundo donax is a PERENNIAL growing to 6 m (19ft) by 4 m (13ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 6. It is in flower in September, and the seeds ripen in October. The species is hermaphrodite (has both male and female organs) and is pollinated by Wind. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very alkaline soils. It cannot grow in the shade. It prefers moist or wet soil. The plant can tolerates strong winds but not maritime exposure.

Height (m): 6

Where it is found

Ditches, riversides and marshland.

S. Europe

Conservation Status: Arundo donax (Giant Reed) Status: Least Concern.

Countries/locations it is found in

How it is used

Food

Rating: 3

Rhizome - raw or cooked. The rhizome can be dried and ground into a powder to make bread, usually in conjunction with cereal flours. It can also be roasted or boiled. Leaves - cooked as a potherb. They are very bitter. The young shoots are used.

Root: includes bulbs, corms, tubers, rhizomes etc.

Medicine

Rating: 2

The root is diaphoretic, diuretic, emollient and galactofuge. An infusion is said to stimulate menstrual discharge and diminish milk flow. A paste of the root is applied to the forehead to treat headaches. Isolated alkaloids have been experimentally shown to raise the blood pressure and contract the intestine and uterus. The rhizome or rootstock is used in the treatment of dropsy. Boiled in wine with honey, the root or rhizome has been used for treating cancer. The plant contains the alkaloid gramine. This is said to be a vasopressor, raising the blood pressure in dogs after small doses, causing a fall in larger doses. The stems have been used as splints for broken limbs.

Diaphoretic: Induces perspiration.

Diuretic: Acts on the kidneys, promoting the flow of urine.

Emollient: Softens the skin, causing warmth and moisture.

Galactofuge: Stops or reduces the flow of milk in a nursing mother.

Hypotensive: Reduces blood pressure, it is used in the treatment of high blood pressure

Other

Rating: 4

Brooms are made from the terminal panicles. Plants are grown alongside irrigation canals to check soil erosion. The plant can be grown as a windbreak screen. If cut down, the culms branch and in this form the plants can be used as a hedge. The leaves can be woven into mats etc, whilst the split and flattened stems are used to make screens, walls of houses etc. A yellow dye is obtained from the pollen. The stems of the plant have a multitude of applications. They are used as plant supports for vines and other climbing plants and to make clarinets, bag-pipes etc. They are also used as pipe stems, for roofing, to make screens, walking sticks and in basketry. They are used to make the reeds of clarinets and organ pipes. The stems can be harvested as desired at any time of the year. The fibre from the stems can be used to make a good quality paper. This plant is currently (1995) under investigation at Rosewarne in Cornwall as a potential commercial paper crop for small-scale industries in SW. England. Because of rather high yields from natural stands, the plant has been suggested as a source of biomass for energy production. Dry cane yields of ca 10, 15, and 20 tonnes per hectare were reported respectively from infertile, partly fertile and fertile soils. According to the phytomass files annual productivity ranges from 10 to 59 tonnes per hectare, the latter figure from Westlake's (1963) estimate of 57 - 59 tonnes. In addendum, Westlake cites evidence that Arundo donax can produce 40–75 MT/ha/yr. in warm temperate and tropical regions. Early vegetative growth has ME (metabolizable energy) of 2.22 megacalories/kg DM, while hay has an ME of only 1.37 (Gohl, 1981). Such annual productivity, if sustainable, makes this a notable energy candidate, especially when one considers the energy as a by-product, with leaf protein and potential pharmaceutical as primary products. A particular type of cellulose is obtained from the plant. In Italy, the plant is used in the manufacture of rayon. Bio-fuel crop.

Basketry: Plant used in making baskets and other items such as chairs. Includes plants that are only used as an ornamental addition.

Biomass: Provides a large quantity of plant material that can be converted into fuel etc.

Broom: Used for sweeping the floor etc.

Dye: Plants that provide dyes.

Fodder: Food given to the animals (including plants cut and carried to them) rather than forage for themselves.

Hedge: Plants that can be grown as hedges.

Musical: Specific mention of plants used as musical instruments. Does not include the various woods that can be used for making musical instruments.

Paper: Related to the entry for Fibre, these plants have been specifically mentioned for paper making.

Pipes: For carrying water etc.

Plant support: Usually bamboos, used as canes in the garden for holding up plants.

Shelterbelt: Wind resistant plants than can be grown to provide shelter in the garden etc.

Soil stabilization: Plants that can be grown in places such as sand dunes in order to prevent erosion by wind, water or other agents.

Thatching: Used for making thatched roofs.

Weaving: Items such as grass and palm leaves that are woven together for making mats, baskets etc. See also Basket making and Fibre.

Fodder: Bank: Fodder banks are plantings of high-quality fodder species. Their goal is to maintain healthy productive animals. They can be utilized all year, but are designed to bridge the forage scarcity of annual dry seasons. Fodder bank plants are usually trees or shrubs, and often legumes. The relatively deep roots of these woody perennials allow them to reach soil nutrients and moisture not available to grasses and herbaceous plants.

Industrial Crop: Biomass: Three broad categories: bamboos, resprouting woody plants, and giant grasses. uses include: protein, materials (paper, building materials, fibers, biochar etc.), chemicals (biobased chemicals), energy - biofuels

Management: Hay: Cut to the ground and harvested annually. Non-destructive management systems maintaining the soil organic carbon.

Minor Global Crop: These crops are already grown or traded around the world, but on a smaller scale than the global perennial staple and industrial crops, The annual value of a minor global crop is under $1 billion US. Examples include shea, carob, Brazil nuts and fibers such as ramie and sisal.

Management: Hay: Cut to the ground and harvested annually. Non-destructive management systems maintaining the soil organic carbon.

Carbon Farming: Plants that can be a critical part of the solution to climate problems. The Carbon Farming Solution - Eric Toensmeier.

Hedge: Hedge

How it is grown

Landscape Uses:Container, Screen, Specimen, Winter interest. Prefers a moist fertile soil in a sunny sheltered position, preferably by water. Tolerates a pH in the range 5.5 to 8.3. Plants can be grown as a specimen in lawns etc, succeeding in quite coarse grass. Plants are succeeding in a site that is very exposed to maritime winds at Rosewarne in Cornwall. Adapted to tropical, subtropical and warm temperate climates of the World, Giant reed is often found on sand dunes near seashores. It tolerates some salt. It grows best along river banks and in other wet places, and is best developed in poor sandy soil and in sunny situations. Said to tolerate all types of soils, from heavy clays to loose sands and gravelly soils. Ranging from Cool Temperate Wet through Tropical Dry to Wet Forest Life Zones, giant reed is reported to tolerate annual precipitation of 30 to 400cm, an average annual temperature range of 9 to 28.5°C and a pH in the range of 5.0 to 8.7. One report says that this plant is only hardy in the milder areas of Britain whilst another report says that it is hardy to between -5 and -10°c. This contradicts with the hardiness zone rating of 6 which would make the plant hardy in most areas of Britain. Plants thrive outdoors at Oxford Botanical Gardens as well as at Hilliers Arboretum in Hampshire and the RHS Gardens in Surrey. Extensively cultivated in S. Europe for basket making etc. Plants rarely if ever flower in British gardens233]. Members of this genus are rarely if ever troubled by browsing deer. Special Features: Attracts birds, Attractive foliage, Not North American native, Naturalizing, Wetlands plant, Suitable for cut flowers, Suitable for dried flowers, Attractive flowers or blooms.

Propagating it: Seed - surface sow in a greenhouse in February to April. Stand the pots in about 3cm of water to keep the soil moist until the seed germinates. It usually germinates in 1 - 3 months at 15°c. When large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first winter. Once they are 20cm or more tall, plant them out into their permanent positions in late spring or early summer. Division in spring. Whilst large divisions can be planted out direct into their permanent positions, we have found that it is best to pot the divisions up and keep them in light shade in a greenhouse until they are rooting away well. Stem cuttings, placed in water, root easily.

Best place to grow: Woodland Garden Sunny Edge; Hedge; Bog Garden;

Habit: Perennial

Hardiness: 6-10

Growth: Fast

Soil: Light (sandy), medium, heavy (clay)

Shade: No shade

Moisture: Moist, wet

Things to keep in mind

This plant can be weedy or invasive. Listed as one of the 100 world’s worst invasive alien species. Primary threats to native riparian habitats. Highly invasive plant in southwestern North American rivers. In New Zealand it is listed under the National Pest Plant Accord as an unwanted organism.

Its other names

Local names

Synonyms

A. maxima.

Giant Reed, Giant Reed Grass Arundo donax