Perth is hot and dry, sure, but there are some differences in garden behaviour among the suburbs. One of these differences, that can have a huge bearing on the success of your garden, is soil. It is important to consider the soil type in your suburb before undertaking any gardening activity, particularly planting and watering.
WHERE TO START!
First, we must know how to identify what soil we are dealing with. Soil can be divided into three broad categories: Sand, clay and loam. To determine which soil best describes that in your garden it is appropriate to do a touch test. In other words, grab a handful.
Sandy soil will be course,
Clay sticky and;
Loam a combination of the two.
Typically, sandy soils will not retain water well but will drain well. Clay soils will retain water for a long period of time which can result in it becoming hard and impenetrable. Loamy soils should, ideally, perform both functions.
Aeolian soils are sandy soils that occur over the majority of the city. Aeolian (by wind) soil can be broken up into subcategories. One common form is Cottesloe soil. Cottesloe soil is prevalent in suburbs such as Fremantle and contains a large proportion of limestone. Some foreign plants will struggle in such soil so it is important to choose plants that will thrive, or at least survive, in sand.
Aeolian soils are formed by wind but that does not mean they are limited to coastal suburbs. In fact, they occur over the majority of Perth suburbs, from Scarborough to Rockingham, and as far east as Bassendean.
Alluvial soils are soils formed by water and include the clay soils found in suburbs such as Guildford and Middle Swan. These soils are far more fertile that Aeolian sandy soils but quite often firmer and will be suitable for a different range of plants.
For an in depth analysis and determination of soil type, there is useful information on soil classification on the website for the Department of Agriculture.
Once you are confident of the soil type you can tailor your watering regime. Clay soils will respond better to prolonged watering, less often. This will allow water to adequately soak in. Sandy soils will benefit from shorter watering periods but more frequent as water will drain away quickly and be wasted. These concepts are handy to consider but it is important not to forget Perth’s water restrictions and your designated watering days.
Get the most out of your soil.
Though residents are urged to adapt to their soil type, there is always room for improvement. Improve your sandy soil by simply adding clay products. This changes the soil structure to a form that is more inclined to retain water and nutrients. Speaking of retaining water, a layer of mulch will prevent water from evaporating quickly off a sandy surface.
Clay soils will respond well to aeration and also, potentially, adding organic matter to improve the structure of the soil. For advice about your soil type, its potential for improvement or how you can adapt, please do not hesitate to contact us.
Commercial and residential bores gain access to Perth’s superficial aquifer, a shared water source below the Earth’s surface. This water is perfect for garden irrigation as it means less reliance on scheme water. This provides both an environmental and financial benefit, especially considering that the majority of most household water bills can be attributed to garden irrigation.
Beyond this, properties with bores have imposed on them more liberal water restrictions, allowing three watering days rather than two. While it is still vital not to over water, this does allow a bit of extra freedom to nurture lawns and gardens.
Bore users will also notice, in general, greater pressure from the bore than off the mains. This allows for more leeway when installing an irrigation system and deciding how many sprinklers can operate on each station. The greater the pressure, the more sprinklers can operate at once. This will reduce the need for extra stations and reduce the potential cost of extra solenoids and pipe. With the extra pressure, bore users will also have the flexibility to add sprinklers to stations without risking a drastic drop in overall pressure.
The Department of Water and Regulation website lays out a groundwater map which provides an approximation of the water table at any given address in Perth. This can be a handy starting point for determining the potential for bore drilling at your property.
The Brighton Third Pipe Scheme is an example of how innovation can allow for the smart and sustainable use of water. The system allows for the community of Brighton (Butler) to source water for irrigation from a series of 5 bores connecting to a local shallow aquifer. It basically allows residents and businesses to source bore water without the necessity to drill a bore on each property.
As with regular bores, this limits the amount of drinking water that gets unnecessarily used on gardens.