We live in a harsh hot spot and water is a precious resource. I believe the Water Corporation is doing a great job in matching demand with supply. As part of their work they are charged with the responsibility of ensuring that we have sufficient water for our wellbeing here in WA. In practical terms this means that we are transitioning from dependence on dams and underground aquifer as our prime water supply to desalination and aquifer recharge. The cost of new water sources is measured in hundreds of millions of dollars. As a result, delaying the capital cost of bringing on new resources, saves massive amounts of taxpayers’ dollars, so that it is a good thing.
Why waterwise gardens?
In the last 20 years we have all become increasingly time poor. This can be a reflection on both parents working, long commutes to work and family demands on weekends. One desire that has sprung from this poverty of time is the “Low Maintenance Garden” which is in many cases seen as a no maintenance garden.
No maintenance is a myth, as even plastic plants and lawn need dusting or sweeping occasionally. So is there a legitimate form of low maintenance gardening?
I believe there are two successful approaches that can give you an attractive garden with a minimum of hard work. Using local area native plants in small pots with a couple of advanced trees or shrubs can give you a mature feel and still bring the benefits of a low water, low fertiliser and low pesticide usage.
A second approach is the use of succulent plants most of which are exotic but now we are seeing an increasing selection of Australian succulents becoming available in garden centres. Succulents can be planted as mature specimens and this helps to give a garden a less raw feel. They too can be planted in autumn and winter and left to fend for themselves as far as watering goes.
Why wildlife friendly?
The world is in the throes of a mass extinction and WA is particularly vulnerable to species loss due to the finely tuned flora and fauna that share our world. One of the great lessons that we have learned in recent years is that every living thing is connected through a complex web of biodiversity. When we plough soil for example we assist the oxidation of the humus layer in the soil which can have a devastating effect on the soil life which in turn supports plant growth and all the organisms that use that plant as food or shelter or for nesting. The death of the good old Aussie backyard with its wide selection of shrubs, trees and lawn has left us with tiny blocks, no room for a vegetable patch or fruit trees or in many cases a single tree. The wildlife corridor created by trees growing along the back fence has gone and this has contributed to making new suburbs wildlife no-go zones. On the other hand, we are facing infestations of midges, flies and mosquitoes. Birds, spiders and micro-bats exact a terrible toll on these nuisance insects. I just learned about micro-bats in the last few weeks, they exist in most Perth suburbs and can consume thousands of mosquitoes in a single night. As a result of habitat loss these tiny flying mammals need assistance with breeding boxes.
What can we do to help to bring wildlife back into our suburbs?
There is no doubt that the leading contenders are the plants that grew originally in your area. A good starting point is to go to your local council all of which have lists of indigenous plants list. Specialist native plant nurseries can help with the sourcing of these plants.
Local plants, once established can survive without summer reticulation and high cost high analysis fertilisers. Small plants planted with autumn and winter rains can survive without irrigation, take root and slowly get growing.
Plants labelled as “Australian natives” confuse many gardeners. Australia is a huge country and when you get to travel around you find that climate, soil and available moisture constantly change as do the plants in response to these variables. So plants from cool climate rainforests in Victoria or alpine plants from Tasmania or even tropical plants from Far North Queensland are equally unsuited to a full sun position in a Perth garden as exotics such as hydrangea, cyclamen and azalea.
In contrast to deciduous trees from the northern hemisphere, which rely on wind for pollination, Australian trees are almost entirely pollinated by other organisms including insects, birds, moths, even marsupials. One local small tree wattle the Coojong Wattle (Acacia saligna) is known to support 130 different species of insects, which in turn become food for a wide range of birds and other local animals including lizards.
What do wildlife want in order to come into your garden?
Essentially this consists of food, water, protection and nesting sites.
One of the critically endangered WA birds that need urgent help is the Carnaby’s Cockatoo. There is a number of different native hakeas, which have large woody fruits that offer food sources for the black and white feathered cockatoos.
In our garden we have a large pecan nut tree in the back garden. The cockatoos monitor the crop with daily visits until the nuts are ripe. Then the whole mob descends on the tree over a couple of days when they strip the fruit and tip-prune the growth leaving an almighty mess on the grass below. We scurry around amongst the debris and collect the many un-chewed nuts for ourselves. If we collected five percent of the total I would be surprised but we’re happy to share the bounty for the privilege of seeing these magnificent birds close up.
Planting other nuts including almonds and macadamias can also give these cockatoos a feed.
Frog friendly gardens need seasonal access to water such as a pond. Predators are likely to be around so we need to build in protection in the form of ground cover plants that can also include some spiny low shrubs such as the Prickly Moses acacia. Predators can also exist in the water so there is no value in having Koi fish in the pond from a frogs point of view as these fish will hoover the eggs up relentlessly ensuring there won’t be another generation of frogs.
We have set up a birdbath just under a tree and this is a meeting point for all manner of birds even though it’s generally one species at a time.
If you are planting shrubs and trees with the goal of attracting nectar-feeding birds, the best approach is to aim for diversity. Here is a cautionary tale of giving birds too much of a good thing. With the arrival in WA of a selection of tropical grevilleas such as ‘Robyn Gordon’, which flower all year round, nectar eating birds such as our local New Holland Honeyeaters and wattle birds were presented with a never ending feast. When the birds started showing signs of poor health an investigation found that these were niacin deficient. Instead of visiting many different nectar sources across the seasons they were honing in on the year round flowering grevilleas.
How do you prepare your soil for planting a waterwise garden?
Most gardeners start out with poor, sandy soil in Perth. Adding compost is the best way to add life to these soils. A quick guide is to dig a hole twice the width of the pot that the new plant is sitting in. Take to plant from the pot and examine the root system. If you can see a pattern of horizontal roots circling the potting mix it’s important to stop this pattern root development by cutting through the roots using a knife and working from top to bottom.
Next use the empty pot as a measure and fill it twice with quality compost, then mix this into the backfill soil. Use this mix to surround the root ball.
I recommend making a saucer shaped moat around the plant to hold water. Next water the plant in well, give it a few minutes to soak in then give it another drink.
It is a good practice to cover the soil with a much to a depth of 50 to 75mm. This helps to hold precious moisture close to the root system of your new plant.
It’s not a good idea to add any fertiliser at planting time, as there is a danger of burning young roots. My approach to feeding is to regularly apply and organic composted mulch to maintain the depth. This might mean a couple of applications per year. Composted mulch breaks down and eventually forms humus in the soil. This is of great benefit to soil living organisms the real drivers of plant growth.
Published on: 18/02/19 11:03 AM