How to have a great lawn in summer in WA
Watch this four minutes video with tips from industry experts and researchers in WA.
There is a tendency to overwater lawn. Although maximum growth rate is achieved by supplying water at about 90% of pan evaporation, healthy minimal growth can be achieved with as little as 30% of pan evaporation. Most amenity turf can be maintained at this lower end of the scale if necessary.
Key factors in producing healthy turf with minimal water are:
- Grow warm season grasses such as Kikuyu, Buffalo season couch, Queensland Blue and Paspalums.
- Control irrigation via soil moisture sensors.
- Design irrigation systems to have uniform application and minimal evaporation losses.
- Improve and maintain good soil structure to maximise water holding capacity and to enable deep-root penetration. This maximises the size of the reservoir of water for the turf.
Design Tips
- Avoid turfing slopes unless absolutely essential.
- Avoid lawn in small areas of median strips, median strips, parking bays etc. These dry out quickly and are prone to overspray and water wastage.
- Where possible, avoid lawn that slopes towards roads and ensure that lawn is not installed too high – ideally should be installed 50mm below curb level to allow for thickening over time.
- Avoid turf use for areas which are not functional, use alternative surfaces for open spaces where recreational zones are not required.
- Minimise use of turf for access, use paths, open gravel areas with trees or shade structures or trafficable.
- Where possible, lay lawn in cooler months so it can get established.
Turf options
Installing a warm season grass correctly helps keep a home cool and saves time on watering and maintenance.
The following lawn varieties are drought tolerant and suitable for WA’s warm conditions:
- Soft leaf buffalo grasses
- Soft leaf – non irritant
- Disease, weed and fungus resistant
- Low allergy
- Low to medium spreading rate into garden beds
- Low maintenance level
- Moderate to good wear, recuperative, self-repairing and becomes green quickly
- Requires minimum 2-4 hours direct sunlight daily
- Soft leaf buffalos should ideally be mown every 7-10 days during summer at a height of approximately 15-20mm and in winter every 3-5 weeks at a similar height.
- Couch grasses
- Soft leaf – non irritant
- Low to medium spreading rate into garden beds
- Moderate maintenance required
- Excellent wear, recuperative
- Responds well to fertilisers and becomes green quickly
- Disease and pest resistant
- Requires minimum 4-5 hours direct sunlight daily
- Couch grasses should ideally be mown every 10-14 days during summer at a height of 10-12mm and in winter it should be mown every 3-5 weeks raising the mowing height to approximately 12-16mm.
- Zoysia grasses
- Soft leaf – non irritant
- Excellent resistance to weeds, pests and diseases
- Excellent cold hardiness
- Easy weed control
- Low water usage
- Less mowing
- Zoysia should ideally be mown every 14-21 days during summer at a height of approximately 15-20mm and in winter mow every 3-5 weeks at a similar height.
Turf options
- Velvetene
- Soft leaf – non irritant
- Non-invasive
- Low maintenance level
- Tolerates high salt environments
- Grows in full sun or filtered shade
- Velvetene should ideally be mown every 7-14 days during summer at a height of 10–12mm and in winter mow every 21-35 days and raise the mowing height to approximately 15-18mm.
- Kikuyu grasses
- Soft leaf – low irritant
- Medium maintenance due to medium to high spreading rate into garden beds
- Regular mowing is required to avoid build-up of stems or runners
- Excellent wear, recuperative and becomes green quickly
- Excellent disease and pest resistance
- Requires minimum 5-6 hours direct sunlight daily
- Kikuyu grasses should ideally be mown every 10-14 days during summer at a height of approximately 12-16mm and in winter mow every 3-5 weeks and raise the mowing height to approximately 16-20mm.
- Queensland Blue
- Soft leaf – non irritant
- Non invasive
- Low maintenance
- Excellent resistance to weeds, pests and diseases
- Minimal thatch
- Immaculate appearance and colour
- Requires 5-6 hours of sunlight per day
- Queensland Blue should ideally be mown every 10-14 days during summer at a height of 10-13mm and in winter mow every 4-5 weeks and raise the mowing height to 14-16mm. Verti-mowing or scarifying in spring is recommended every 2-3 years.
Six steps for successful planting
We recommend you follow these steps when planting your lawn:
1. Clear the Site: Remove any rocks, sticks or tree roots and level the area with the back of a rake or levelling board to create a smooth and consistent soil surface about 30-50mm below the level of paths and driveways.
2. Install irrigation: You will need to design and install an efficient irrigation system. A Waterwise Garden Irrigator can provide expert advice and design and install a system to ensure the new lawn will receive the right amount of water on your sprinkler roster day.
3. Soil preparation: Incorporate soil amendments appropriate to your soil type, (for example by adding clay or red sands to your grey sands), working them into the top 15cm of soil. Add a quality soil wetting agent and a moisture retainer if possible (see your turf grower for advice) and lightly apply an organic, slow release fertiliser and water in well. This will provide a healthy base for your lawn. Look for the Waterwise and Smart Approved WaterMark symbols when purchasing a gardening product at your local Waterwise Garden Centre.
4. Lay your turf: Begin by laying the turf along the longest straight edge, such as a driveway, pushing the edges tightly together without stretching the turf or overlapping. Stagger the joints like brickwork and use a sharp knife to cut the turf where required. If you’re installing turf on a sloped surface place the turf along the slope, not down and peg or stake the turf where required to keep it in place. After laying the turf, use a roller to encourage soil to turf contact, lightly apply a slow release fertiliser and water thoroughly. Re-apply a light sprinkle of organic fertiliser, such as pelletised chicken manure, 14 days after laying.
5. Watering: Establishing a new lawn requires additional watering in the first few weeks. You can apply for an exemption to the watering roster to help fully establish the lawn on behalf of your client. To find out more or to apply contact Water Corporation on 13 10 39. Once the exemption period finishes, you will need to revert to the watering roster.
6. Mowing: Lightly mow the new lawn once you are certain that the roots have taken hold. In summer this is usually within 10-14 days of laying your turf.
Maintaining a healthy lawn
To keep lawn looking great it requires maintenance throughout the year including watering, mowing, fertilising, top dressing and de-thatching. Advise your client to apply a soil wetting agent at least three times a year, at the beginning of spring, the beginning of summer and again mid to late summer. Ensure they follow the manufacturer’s application and safety instructions.
Watering roster
Once a lawn is established watering can only be once on the rostered watering days, either before 9am or after 6pm. It’s best to water early in the morning as it allows the water to soak to the roots and be available throughout the day when it needs it most. To find out your rostered watering days or for a recommended watering schedule visit watercorporation.com.au
Fertilising
By fertilising your lawn you’re providing it with a range of nutrients for good health and growth. Apply a slow release fertiliser every two months during the warmer months and once during winter. The manufacturer’s recommended fertiliser application rate is the maximum amount that should be applied. Remember that if you apply fertiliser excessively, whatever your lawn doesn’t use ends up in our waterways.
Mowing
Mowing the lawn will help to keep it healthy and looking great. During summer a lawn will require more frequent mows (make sure the mower blades are sharp) every 7-21 days to a height of 10-20mm depending on the variety. Please refer to the individual recommended heights mentioned previously under turf options.
More Information
For more information on establishing and maintaining a healthy, warm season lawn visit the Turf Growers Association WA at www.tgawa.com.au
Lawn establishment and recommended irrigation scheduling
(refer to Exemptions in Appendix C) Autumn and Spring (March – May, September – November) Recommended as a good time to establish new lawn
| DAYS | APPLICATIONS PER DAY | APPLICATION (mm) |
| 1-14 | 2 | 4 |
| 15-28 | 1 | 7.5 |
| 29-35 | every second day | 7.5 |
| 35+ | rostered sprinkler days | 7.5 |
Summer (December – February)
| DAYS | PPLICATIONS PER DAY | APPLICATION (mm) |
| 1-14 | 3 | 3.5 |
| 15-21 | 2 | 5 |
| 22-28 | 1 | 10 |
| 29-35 | every second day | 10 |
| 35+ | rostered sprinkler days | 10 |
Winter (June – August) Recommended as the ideal time to establish a new lawn. Winter sprinkler bans apply
but exemptions are available for establishing a new lawn. On wet days the sprinklers
should be turned off.
| DAYS | APPLICATIONS PER | APPLICATION (mm) |
| 1-7 | 2 | 2 |
| 8-14 | 1 | 4 |
| 15-30 | every second day | 4 |
Soil moisture sensors
Soil moisture sensors appropriately calibrated for the conditions and hooked to an irrigation controller can be very useful for irrigation scheduling.
There are a large range of sensors available but inexpensive soil moisture probes which indicate when the soil reservoir is full and when it needs to be topped up are all that are required for most practical amenity turf situations. The simplest way of using a moisture sensor is to install it just above the depth to which you want water to move into the soil.
Irrigation methods for turf
Turf is irrigated either via or drip systems. The key elements with sprays are to have spacing close enough to provide uniformity and to reduce misting by using sprinklers which have minimal evaporation from large droplets.
(For more information refer to the Irrigation Section)
Lawn Maintenance Tips
- Apply granular fertilisers in spring and autumn at the rate of 50g per square metre. Spread the fertiliser on dry turf and water in.
- Maintain strong healthy turf without excessive growth in the warmer months by
- spraying with liquid fertiliser containing seagrass, fish, organic compounds and amino
- acids at four weekly intervals. Several brands of these low analysis fertilisers are
- readily available and easy to apply. Slow release fertiliser is preferred.
- Avoid ‘scalping’ the lawn when mowing and never remove more than 1/3 of the leaf blade. (this is especially important for Buffalo lawn).
- Apply wetting agents at least twice a year – usually in spring and late summer.
- If root zone becomes clogged by root proliferation and compaction, cultivation in the form of coring or spiking may be required to increase the infiltration rate.
- To incorporate compost into an existing lawn, mow the lawn at a height of 10-20mm and remove all clippings and debris. Aerate the soil and relieve compaction with a hollow tine machine. Mix the surface material with 1-3L of compost per square metre, slow release fertiliser, zeolite, minerals and a blend of rock dusts.
