New Gardens
We only get one good chance to set up a home garden which will be water efficient throughout its lifetime. That chance comes when the garden is about to be constructed on your brand new home site.
Whatever style of garden you may have in mind, the Waterwise planning and much of the construction you do now, will determine how efficiently you are able to water in the future. Many of the things which can be done at this stage, would be very difficult to put in place or change later.
Include the tips that follow, and your chosen garden will be healthy and Waterwise forever.
Please Note: There are water efficiency measures in place for Western Australia. If your plants need to be watered more frequently than the watering roster for your area allows, additional watering will need to be done with a hand held hose.
Planning your new Garden
The time spent planning your garden is very well invested.
You will need to start with a plan of your allotment:
- First, walk around your block. Consider the overall landscaping framework, and the things which will constrain your garden - position of house, areas to be screened out, views to be featured, approaches to the house, streetscape, passage of the sun, slope of the land and so forth. Within that framework, start to envisage the general form of your garden.
- Block out on your diagram all those areas which won't be planted or watered. Consider things like house foundations, garden sheds, extra parking, paths, patios, composting area, mulch stockpile, and clothes drying.
- Having defined the areas of open space, subdivide them into those parts which must be grassed (for example play areas); and those which can have a more water efficient treatment. You may perhaps choose an attractive ground cover for visible but low traffic sections. Or utility areas may be earmarked for a hard mulch such as crushed brick. Picture how each element will fit with the total landscape.
- Consider the areas selected for turf, and ensure they are shaped to suit the watering patterns of your proposed irrigation equipment.
- Choose a turf suited to our climate. Warm season grasses include cultivars and hybrids of couch, such as Bermuda, Santa Anna, Greenlees Park, Wintergreen, Windsor Green and CT-2. These turfs have a relatively low water demand and high drought tolerance.
- What is left will form your garden beds. It is critical to your future watering program that these areas be divided into Watering Zones - groupings of plants and trees with similar watering requirements. (Our Watering Zone pamphlet explains how each zone is watered more or less often than the others - ring 13 10 39 for your closest pamphlet supplier):
- Group your high water demand (zone 3) plants where they will be most visible and appreciated. Put intermediate plants (zone 2) and water misers (zone 1) in other, separated locations. Naturally, you may have a number of versions of each zone, in various locations.
- Specially labelled plant selections for each watering zone are available from most plant nurseries. Ring our Helpline (13 10 39) for your local suppliers. They will also have listings of common plants, climbers, groundcovers, shrubs and trees appropriate to each zone.
- Consider the prevailing dry, hot summer winds and summer sun, and plan-in permeable windbreaks and shade plants accordingly.
Planning an automated irrigation system
Modern irrigation systems are both cheap and adaptable. When properly designed and operated, they provide effortless and very efficient watering. Your planning should consider these elements:
Source of supply.
There are two choices - bore or mains. In either case, the supply pressure must be matched to your irrigation systems. Too much pressure results in two major contributors to water wastage - evaporation loss through misting, and uneven application. Too little pressure causes poor distribution also.
- Groundwater bore. This is a cheap, environmentally friendly option in many areas - check out suitability and prices through your Irrigation Australia (IA) accredited irrigation supplier. Consider sharing a bore under a protective legal agreement with your neighbours. And limit pump size to your planned system's pressure requirements.
- Scheme water. If you choose to pay as you use, an accredited installer will fit a mandatory back-flow preventer, and if you wish a filter. He can also pressure test at the mains offtake, and advise if a pressure reducing valve is advisable. A simple diaphragm valve will usually be sufficient.
Lawns.
Turfed areas will command a major portion of your total water use. Considerable savings will be made by including these features in your system:
- Ask for emitters which provide coarse drops, preferably at a low trajectory. These will minimise evaporation. Gear drive sprinklers and impact sprinklers are best where large, regular areas are involved. Pop-up sprays are appropriate for smaller areas of lawn. Your Irrigation Australia (IA) supplier will advise.
- Choose spray heads to closely match the outlines of your lawn. This will minimise overspray onto paths and gardens. A range of spray patterns are available.
- Purchase the highest quality emitters you can afford, and standardise on that brand - at least within each watering station. Uniform distribution is a critical consideration in water saving.
- Locate your pop-ups at the intervals recommended by the manufacturer - usually spray head to spray head - and staggered if in rows.
- When defining the watering stations and locating the main lines, be sure that the lawn and each garden watering zone are on separate programs.
Garden areas.
The important thing to remember here is to water directly onto the root zone - not onto the leaves, and not onto the areas between plants.
- Shrubs and perennials. Use drippers to individual small plants. When choosing components, work on providing 10 litres per square metre of watered soil. This corresponds to the Perth Standard Drink of 10 mm depth of precipitation.
- Larger shrubs and fruit trees. Low pressure micro-irrigation sprinklers spread water across the entire drip zone. Their low trajectory undershoots foliage, and avoids wind losses.
- Bedding plants. Large beds of densely planted flowers can also be watered by low pressure micro-irrigation sprinklers. Smaller beds may need Micro-sprays, but these must be on a pressure regulated line to avoid misting
- Pot plants and hanging baskets. Use drippers or multi-outlet emitters to each plant. Water storing granules mixed through the soil save water and improve distribution through the mix.
- Fernery, shadehouse and greenhouse. In very sheltered locations, tropical plants and seedlings will appreciate the humid micro-climate created by misting sprays.
Garden Construction
Ready to roll the sleeves up? Well, there is one last little bit of planning to do first.
Construction planning.
If you intend to build your garden yourself, give some thought to how the work should be sequenced. Building a garden in your spare time can stretch over many months - and stretch many muscles! Here is a typical sequence:
- Drill and install bore and pump (if applicable).
- Finish off any changes in level, and install retaining walls as necessary
- Lay driveways, paths and paved areas. This reduces dirt trails into the house. Place conduits under any paving to be crossed later by irrigation mains and wiring.
- Carry out soil conditioning as appropriate for lawn areas, and those large garden areas (eg vegetable patch, bedding plants) requiring total-area soil improvement.
- Place inorganic mulches such as cracked laterite
- Trench and lay the PVC irrigation mains and station solenoid wiring; and the PVC lawn laterals. Flush lines and fit pop-ups.
- Install 13 mm low pressure tubing through the garden area, keeping each zone on a separate station
- One zone at a time, select and plant out garden areas and ground covers
- Connect 4 mm poly tubing and appropriate emitters at each plant. Set up the zone watering schedules
- Lay turf
- Contact the Waterwise Helpline on 13 10 39 to apply for a watering exemption and commence the lawn-establishment watering schedule
- Lay garden mulch
Resourcing.
You can either do it all yourself; employ a landscaper or irrigation specialist; or do some mixture of both. The Waterwise Helpline (13 10 39) will locate tradespeople in your area with Waterwise knowledge.
A Waterwise Rebate for a new Waterwise Irrigation System is available per residential property. For more information, visit www.water.wa.gov.au
Paving.
Bricks and cement don't need much watering, but if unshaded they store and radiate a lot of heat. Look to compliment them with shade trees or constructions.
Soil improvement.
This is a very important element in long term water efficiency, and difficult to address after the garden is completed. Mixing organic matter such as compost into the soil, or purchasing an appropriate soil blend, dramatically improves both water and nutrient holding capacity.
- Lawn. Rotary hoe extra organic matter through the top 15 to 20cm of soil. This allows smaller 'drinks' and longer periods between watering. In turn this encourages a deeper, drought resisting root system and a more efficient growth pattern.
- Watering Zone 1. These plants have evolved under our local conditions, or in parts of the world with similar soils and climate. Generally they need little soil improvement.
- Watering Zone 2. These plants are not quite so heat and drought tolerant, and respond well to good soil preparation. Dig a hole 30 cm deep and 3 times the diameter of the pot. Fill with a 50/50 mixture of soil and rotted animal manure; or soil and compost; or a purchased blend.
- Watering Zone 3. These plants are right out of their natural element, and must have the level of soil improvement detailed above to survive and thrive.
Soil wetting agents
May need to be used on sandy soils which repel water. Those soils may occur in both lawns and garden beds. Treatments should be applied in Spring
Irrigation system installation.
This is another critically important stage, as changes are difficult to make later.
- detailed advice on installation is available through your irrigation retailer. Follow the manufacturers' instructions carefully. In particular, do not 'economise' by allocating too many emitters to any one station; or placing pop-ups too far apart.
- once installed, lawn spray heads should be adjusted to throw the correct distance
- in the garden, drippers and microsprays can be installed progressively, as planting takes place
- most garden emitters are designed to operate at low water pressures. Ensure each garden station is fitted with a flow reduction valve at the inlet.
- garden emitters such as micro-irrigation sprinklers, drippers and greenhouse misters have fine valves and are easily clogged. Each station should incorporate an in-line filter.
Programming the Controller
- set the start time to early morning, to reduce evaporation losses caused by sun and wind
- program a separate watering frequency for each watering zone, as detailed in the Watering Zones pamphlet
- set the run-time required to give your lawn a Standard Drink. The Waterwise Catch Cups available from irrigation stores, are designed for this purpose
- set the run-time required for each of your garden Watering Zones. The objective of a dripper system is to supply a Standard Drink of 10 litres / m2 of ground beneath each plant's leaf canopy. In practice this means selecting a run time which will cater for the 'average' size plant on the line. Variable-flow drippers can then be used to fine tune watering to smaller or larger plants. Larger shrubs may need a number of drippers spread over the root zone. If low pressure sprinklers are required to water trees, they must be on a separate line to the drippers
- Ensure the settings adhere to the water efficiency measures for your area
Planting.
Generally planting will be done progressively, one zone at a time, and as funds and time permit.
- improve the soil as previously detailed for the zone. Soil improvement need not extend beyond the anticipated boundary of the drip zone
- plant according to the instructions on the label, finishing the ground into a shallow depression around the plant
- plants generally need liberal watering until they are established
Roll-on turf lawns have shallow roots on installation, and need special watering until established.
Mulches.
Organic mulches, as distinct from inorganic mulches like gravel or crushed brick, can be divided into two types:
- soft mulches break down to rejuvenate the soil and feed the plant. They retain moisture, encourage earthworms, and cool the soil. They should be placed under the drip zone of the plant, so that nutrients seep through to the main concentration of roots. Soft mulches include materials such as compost; pea-hay or lucerne-straw; karri mulch; peat moss or seaweed. Composts may be enriched with animal manures.
- hard mulches are used between plants, to reduce evaporation losses from the soil, discourage weeds and improve the appearance of the garden. They need not be watered, and should not be of a type which retains moisture. Chipped tree waste is an ideal material, particularly from species like eucalypts, bottle brush or Geraldton Wax. Pine bark or industrial woodchips are also suitable.
Maintenance Planning. It is useful at this stage to consider the impact of your chosen garden design, on routine maintenance. Your future programme might consider:
- composting
- mulch replacement
- emitter and filter checks
- seasonal watering schedules
- fertilising
- mowing
- pruning
- pest and weed control
Time spent planning your garden is well invested. The tips on this website will ensure your new garden is healthy and Waterwise.
Seasonal Irrigation Schedules - New Gardens Only
The details which follow are calculated on the basis of average Perth weather conditions. They assume improved soil prior to garden installation.
However, there are water efficiency measures in place for Western Australia. If you are establishing a lawn or garden you may apply for an exemption in order for it to become fully established. Please call 13 10 39 for more information.
Autumn or Spring Establishment
March through May or September through November
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Winter Establishment
June through August
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Summer Establishment
December through February
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Once your garden is properly established you should reset your controller to the watering days allocated to your property.
Click on the relevant link below for the Watering Roster for your area.
Watering Roster Perth and Mandurah