Arundo donax - Giant Reed

Family:	Gramineae
Habit:	Perennial
Height:	6
Width:	4
Synonyms:	A. maxima.
Range:	S. Europe

Arundo donax (Giant Reed) is a Perennial which grows to a height of 6m and a width of 4m . It has a hardness rating of 6.
Giant Reed will flower in March. the seeds ripen from April
The flowers from this plant are hermaphrodite (has both male and female organs) and they are pollinated by Wind

Soil Information

Giant Reed will grow in light (sandy),medium (loamy),hard (clay) soil. It is / is important for the soil to be well drained.
The soil prefers the following PH / acid levels :
- pH of less than 6, Acidic soils
- pH between 6 and 8, Neutral soils
- pH greater than 8, Basic soils
Giant Reed prefers soils

Ideal Planting Locations

Giant Reed should not be planted in shady areas.

Ditches, riversides and marshland[7, 200].

Planting places suited to this plant described below.

• Grows within a woodland garden
• Grows on a sunny edge
• Can be used as a hedge
• A bog garden plant

Cultivation Details

Prefers a moist fertile soil in a sunny sheltered position, preferably by water[1, 134, 200]. 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[233]. Plants are succeeding in a site that is very exposed to maritime winds at Rosewarne in Cornwall[K]. 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[269]. One report says that this plant is only hardy in the milder areas of Britain[1] whilst another report says that it is hardy to between -5 and -10°c[200]. This contradicts with the hardiness zone rating of 6 which would make the plant hardy in most areas of Britain[200]. Plants thrive outdoors at Oxford Botanical Gardens[233] as well as at Hilliers Arboretum in Hampshire and the RHS Gardens in Surrey[K]. Extensively cultivated in S. Europe for basket making etc[50]. Plants rarely if ever flower in British gardens233]. Members of this genus are rarely if ever troubled by browsing deer[233].

Edible Uses*

* See disclaimer
Edible Rating: 3/5
Rhizome - raw or cooked[84]. The rhizome can be dried and ground into a powder to make bread, usually in conjunction with cereal flours[7, K]. It can also be roasted or boiled[84]. Leaves - cooked as a potherb[84]. They are very bitter[177]. The young shoots are used[177].

• Leaves -
• Root - includes bulbs, corms, tubers, rhizomes etc.

Medicinal Uses*

* See disclaimer
Medicinal Rating: 2/5
The root is diaphoretic, diuretic, emollient and galactofuge[7]. An infusion is said to stimulate menstrual discharge and diminish milk flow[240, 272]. A paste of the root is applied to the forehead to treat headaches[272]. Isolated alkaloids have been experimentally shown to raise the blood pressure and contract the intestine and uterus[240]. 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[269]. 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[269]. The stems have been used as splints for broken limbs[257].

• 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

Propagation

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[134]. 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[1]. 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[1].

Known Hazards

None known

Other Uses

Brooms are made from the terminal panicles[7]. Plants are grown alongside irrigation canals to check soil erosion[169]. The plant can be grown as a windbreak screen[1, 169]. If cut down, the culms branch and in this form the plants can be used as a hedge[236]. The leaves can be woven into mats etc, whilst the split and flattened stems are used to make screens, walls of houses etc[46, 50, 61, 84]. A yellow dye is obtained from the pollen[257]. The stems of the plant have a multitude of applications. They are used as plant supports for vines and other climbing plants[7, 169, 269] and to make clarinets, bag-pipes etc[46, 61, 103]. They are also used as pipe stems[84], for roofing[46], to make screens, walking sticks and in basketry[100, 195]. They are used to make the reeds of clarinets and organ pipes[236]. The stems can be harvested as desired at any time of the year[269]. The fibre from the stems can be used to make a good quality paper[269]. This plant is currently (1995) under investigation at Rosewarne in Cornwall as a potential commercial paper crop for small-scale industries in SW. England[K]. Because of rather high yields from natural stands, the plant has been suggested as a source of biomass for energy production[7, 269]. Dry cane yields of ca 10, 15, and 20 tonnes per hectare were reported respectively from infertile, partly fertile and fertile soils[269]. 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[269]. 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[269]. A particular type of cellulose is obtained from the plant[7]. In Italy, the plant is used in the manufacture of rayon[269].

• 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.
• 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.

Cultivars

no recorded cultivars

References

Flora Europaea
?
Author: ?
Rating:
Publisher : An immense work in 6 volumes (including the index). The standard reference flora for europe, it is very terse though and with very little extra information. Not for the casual reader.
Date of Publication : 1964

The New RHS Dictionary of Gardening. 1992.
Huxley. A.
Author: Huxley. A.
Rating:
Publisher : Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
Date of Publication : 1992

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