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Edited by John Colwill - Local gardening expert

In the Perth area approximately 60 percent of all scheme water used goes on watering the lawn and garden. While grassed areas provide many practical benefits in a garden landscape, good design, thorough preparation, careful consideration of what type of grass is planted and good management will result in significant reductions in water use.

Before planting lawn you will need to investigate and analyse

• Orientation, sun and shade.
• Topography, water run off.
• Soil types, water holding capacity, compaction, water repellence, fertility levels.
• Availability of accessible ground water
• Views both inwards and outwards.
• Utility spaces (clothes drying, compost and storage areas).
• Outdoor living spaces (barbeques, seating areas).
• Special needs (vegetable garden, swimming pool, etc).
• Functional and aesthetic requirements.
• Functional and aesthetic requirements.
• Maintenance expectations.
• Budget available.

General design principles

• Maximise the use of non-planting treatments such as paving and mulches. 
• At the same time, beware of excessive unshaded paving which can be hot and glaring.
• Plant lawn after considering your functional and aesthetic requirements.
• Lawn areas should be designed and sited to be practical, and should never be used as a ´fill in´ material where nothing else could be thought of.
• Avoid planting lawn on slopes, or in narrow necks or paths which are difficult to water efficiently and maintain
• Obtain expert advice on irrigation from Irrigation Australia (IAL) members. Most offer a free no obligation design service.
• Choose a lawn type that is water efficient and best suited to your soil. Members of the Turf Growers Association will advise you on the most suitable type.
• Prepare soil before planting new lawn. Improved water efficiency can be achieved with a small amount of soil additive (such as compost  Click here to find the best compost for you.) added and rotary hoed to a depth of 100 - 200 mm.

Choice of variety

Warm season grasses such as common or Bermuda Couch and various cultivars or hybrids of couch sold as 'Santa Ana', 'Windsor Green', 'Greenlees Park', 'Wintergreen' and 'CT-2' have the lowest water demand. They also have a high drought tolerance.

Other warm season grasses such as 'Buffalo', 'Kikuyu' and 'Saltene' have an intermediate water use rate and a reasonably good drought resistance.

Cool climate grasses such as 'Ryegrass', 'Kentucky Blue' and 'Bent Grass' have high water use rates and only a fair to poor drought resistance. A summary of the important characteristics of the most common lawn grasses is given in table form.

 

Methods of planting

There are three ways to establish a lawn

• Turf rolls provide the most water-efficient means of establishing a lawn in summer, with an instant cover from the start. It is possible to establish during summer on one watering a day providing that the soil underneath has been well prepared.
• Seed should only be sown in autumn and spring.
• Runners can also be planted all year round though it is best to plant them in the cooler months of autumn and spring.

Maintenance

• Fertiliser use is closely linked to water use. Cutting down on the amount of water used also means you can cut down on the amount of fertiliser. The recommendations on the bags should be regarded as maximum levels.
• Fertilisers which have some animal manure content help to maintain the organic matter level of the soil.
• All fertilisers should be applied immediately before a watering.
• Mowers should be set so that only one third of the leaf area is removed at any one time. This should leave a grass blade length of some 10 to 15 mm. This amount of leaf shadows the soil surface and thus reduces evaporation loss.
• Since the growth rate of warm season grasses slows down in cold weather the mower blades should be raised another 5 mm or so during winter.
• Only top dress to even out bumps and hollows and then only use special top dressing mixes which contain organic matter.  Compost makes great organic matter. 

Your Guide To Lawns

Variety	Water use	Drought tolerance	Fertiliser requirement	Heat tolerance	Shade tolerance	Wear resistance
Couch
Bermuda (common)	Low	Very high	Med/high	Excellent	Poor	Very poor
Santa Ana	Low	High	Med/high	Excellent	Medium	Good
Greenlees Park	Low	High	Med/high	Excellent	Fair	Fair
Wintergreen	Low	High	Med/high	Excellent	Medium	Good
Windsor Green	Low	High	Med/high	Excellent	Medium	Good
CT-2	Low	High	Medium	Excellent	Fair	Good
Saltene	Medium	Medium	High	Excellent	Medium	Good
Buffalo	Medium	Fair	Medium	Excellent	Good	Fair
Kikuyu	High	Good	Low	Excellent	Poor	Very good

Lawn problems associated with watering

• Brown patches in a lawn may indicate either poor water distribution or areas of non-wettable soil.
• Thatch contributes to the development of non-wettable soils and should be reduced by a hard mowing in spring or the use of a de-thatching machine. Non-wettable soils should be treated by the regular use of soil wetting agents each spring.
• Overwatering of lawns, particularly when the water is applied in the evening, can lead to the development of fungal problems. Check your application rates and timing.
• Moss growing in a lawn may indicate excess water application and/or poor drainage and/or insufficient sunlight.

Establishing a new lawn

Organic matter mixed through with the top 15cm of a sandy soil will dramatically improve both water and nutrient holding capacity.
Do this before a lawn is established.  To find the best organic matter for your garden, click here.

The extra organic matter enables longer periods between watering which encourages a deeper root system and a more efficient growth pattern.

Prepared with the support of the:
Nursery & Garden Industry Association,
Irrigation Australia,
Australian Institute of Landscape Architects,
Turf Growers Association,
Landscape Industry Association,
Independent Lawn Mowing Contractors.