Drought Tolerant Couch Grass Trials at Parliament House
Landscape Services are currently trialling four different types of couch grasses. These couches are being assessed for ease of establishment, water usage, fertilizer requirements, wear tolerance and general appearance right throughout Canberra’s seasons.
The aim of the trial is to determine the most suitable couch for use at Parliament House, taking into account the above factors.
The trial is taking place on the House of Representatives side of Parliament House on the north east and south east corner lawns, the Senate playing field and the viewing strip north of the senate playing field. Visitors are invited to view the trials at any time.
The four different varieties of couch being trialled are: Conquest, Grand Prix, Santa Ana and Legend. All varieties were installed in early January 2008 using turf roles. Conquest (left of the Anzac memorial sculpture) and Grand Prix are situated on the north east corner lawn. Santa Ana (closest to Manuka) and Legend are situated on the south east corner lawn.
Photos taken 8/2/08 from the NE corner lawn (first photo)
and the SE corner (second photo)
During establishment the couch is being irrigated using pop-up sprinklers twice per evening for 4 minutes depending on weather conditions, rainfall etc. The amount of evapo-transpiration (ET-combined water lost from the plant and evaporation) replaced by the irrigation system during establishment is 90%. It is expected that a visually acceptable couch surface can be achieved with only 35% of ET. The replacement ET levels will be gradually reduced as the turf establishes.
The turf trials are currently being mown as needed (approx 2-3 times per week) at a height of 2 inches using rotary mowers. This mowing height will soon be reduced to 1 inch to encourage lateral growth and a more uniform surface.
The area was prepared and before the couch was unrolled a starter fertilizer was applied at a rate of 10g/m². A slow release fertilizer was applied late in January at a rate of 27g/m².
The colour and texture of the couches is being assessed. Conquest (sourced from Sydney) appears to have a lush green colour comparable to some cool season turf species. Grand Prix (sourced from Melbourne) possesses a very fine texture and more of a light green colour. Santa Ana (sourced from Sydney) and Legend (sourced from Canowindra) are more of a blue/green colour.
The trial is still in establishment phase but regular monthly observations will be posted as the trial continues.
In December 2008, the Senate playing field was line planted with Grand Prix and the viewing strip north of the playing field was planted with Conquest. Grand Prix and Conquest have been performing very well in the original trial plots and it was decided to extend the areas of these two couches so further evaluation could occur, with these varieties growing under different conditions.