Thursday, November 5, 2009

Grow your own Thatch

Phragmites australis
(Phragmites communis)
This is the plant you need, if you want to thatch your roof with a long-lasting home-grown product.

These plants are growing in the pond at Peacehaven Botanic Park at Highfields.

“Common reed” is a cosmopolitan plant, native to many areas of the world including Australia and Britain, where it is known as “Norfolk Reed”. (The name “australis” is Latin for “southern” - not “Australian” as Australians sometimes believe.)
In Europe, the plant is grown in specially cultivated reed beds, to supply the thatching industry. For good thatch, the whole crop should be cut each year, so that next year’s crop contains no dead reeds. A roof of these reeds can be expected to last for 50 or 60 years.
Thatch roofs have never caught on in Australia, though. Perhaps the bushfire hazard is a little too obvious!
Common reed is used around the world for making all sorts of things, from mats, baskets, and hut walls, to pens and arrow shafts. Its pretty purplish-brown plume-like seed heads are valued by florists.
In Australia, it is a “bush tucker” plant. The fresh root-tips (rhizome-tips, really) are produced in spring, and said to have a delicious flavour, like asparagus. They can be cooked in much the same way.
Not a true reed, this is actually a species of grass, but it grows in water like a reed. Others might suggest that it grows like a weed. It is certainly a very vigorous plant. With its strongly spreading rhizomes, it can easily fill a dam or pond.
It does have very high value as a refuge and nesting site for wildlife, and is grazed by stock. It can prevent erosion, tolerate salinity, grow in water or mud, and thrive in water as acid as pH5.5, or as alkaline as 8.7. Its only demands are full sun and enough water.
It is suitable for use in a planted wetland for purification of greywater, urban run-off, or even sewage waste. (For these purposes, it needs to be harvested annually. Pollutants are removed with the stems, and new growth takes up further pollutants as the plants regrow.)
Cutting below water-level in autumn kills the plant back, a useful technique where control is needed. If vigorous growth is what you want, it should be cut in back spring

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