Episode: Four
Date: 29th March 2008
Presenter: Neville Passmore
Story Title: Mitre 10 Project Gardens- Watersaver Garden

This week’s Mitre 10 project focuses on thinking for the future. At the Garden Gurus we always like to strive to create gardens that can be self sufficient and not rely on the environments precious resources water, therefore we are giving you some tips on how you can save every little drop and reduce your environmental footprint.

Step 1: Design for Low Water

Clues:
Check out the natural bush land near your home and have a closer look at the types of plants growing together. Observe the species, shapes and sizes of the plants. Observe how they grow together, their spacing, the protection they provide each other, the mulch on the soil surface and so on. Take a few pictures so you can later identify the species and think about application at home.

Grouping:
Some plants need lots of regular water, some barely any. By grouping plants with similar thirst you can reduce your water use because you don’t have to water the whole garden just to cater for most thirsty plants. Water the thirsty ones when they need it and the others less often.

Micro Climate:
There is a huge difference in temperature when in the shade especially shade from trees. You may need to carefully plan the location of taller plants to the south of shorter ones that need full sun. By covering the ground with a living “coat” meaning plants at different levels, you will reduce evaporation, and create a more constant ground temperature in summer and winter. Also it will create a healthier environment for other living creatures (such as insects, frogs, birds and lizards) that generally assist with plant health.

Advice:
Get some advice from your friendly local Mitre 10 centre staff.

Step 2: Water Saving Plants

There are thousands of plants available that could be classified as ‘low water use’ plants. On the Mitre 10 Plan check out the list of Water Saving Plants many of which are Australian natives.

Step 3: Reduce Water Loss

Water is can be lost in two ways: evaporation and runoff.

Evaporation:
Water on the surface of soil and pavement will generally evaporate fairly quickly. Obviously you should avoid watering your driveways, pathways and buildings. Water that does land on the soil, should soak up quickly so it will be available to plants and not lost to the sun and wind. Natural topsoil’s are generally poor in Australia because they have been depleted through building and farming activities. To create a topsoil with good drainage you’ll need to break down clumpy, solid soil (such as clay) with an additive such as “GroundBreaker’; and dig in large amounts of compost. Mulch is also a fantastic way to reduce evaporation. Cover the soil with about 75mm of mulch. The purpose of this layer is to insulate the soil from the sun and wind and other important functions such as providing nourishment for plants and a habitat for creatures. Depending on the plants you intend to grow, you many also have to adjust the pH (acidity or alkalinity) of the soil.

Runoff:
Runoff can occur for many reasons, mostly because pavement is watered, but often water will ‘bead’ on top the soil and runoff without soaking it in. Soils can become hydrophobic (repellent to water) and can be remediated as described above, or they can be treated with agents that will help them to take water in.

Step 4: Collect Water

Rainwater:
Roofs are efficient water collectors just waiting for you to exploit. You can collect and store water from houses, sheds, carports and pergolas- even on the tiniest of blocks. The roof of your house isn’t the only rain-collector available to you. The ground itself receives the same amount of rain, so think about how much water the soil can absorb, and how you can drain pathways and paving into the garden beds and lawns.

Grey water:
The average household produces 400 liters of grey water per day. If you can use it all to replace drinking water that you would have used for watering plants you could save around 140 thousand liters if drinking water every year! Greywater is the water from showers, baths, spas, hand basins, laundry tubs, washing machines, dishwashers and kitchen sinks (although kitchen water is generally contaminated). You can re-use any waste water from your home, but Blackwater must be treated by an approved sewage treatment facility before the water may be legally used for any other purpose. Before you spend too much time and money on diverting greywater, check with your local authorities (see your water bill) to find out what you can and cannot do. If you stick to the guidelines you can save large amounts of water and money, keep a green garden and know that you’re doing your bit for the environment.

Step 5: Water Wise

Water will generally evaporate before the plants can make any use of it, so be a little inventive with methods of introducing water deeper into the soil.

Send it Down:
If you are renewing your garden and lawn you should consider installing perforated agricultural pipe (ag-pipe for short) to use as a deep watering system as well drainage. You may have seen councils use them as a method of deep watering the trees that grow in the tiniest of holes in street pavement. You can connect these pipes to you storm water system in a variety of ways, depending on your homes specific situation. You can also water deep down with your hose by using a “Water Spike”. It is simply a long metal tube with a hose connection. As you push down the spike, with the running water, it easily penetrates deeply into the soil.

Quick Fix
Cut the bottoms off plastic drink bottles, remove the lids, and bury them at least half-way down in the soil next to a plant. Fill the bottle when you water the garden and this little reservoir will trickle-feed the plant for 24 hours or more. Even easier, buy a set of watering spikes and attach the bottles to them.

Wise Irrigation
Spray and sprinkler irrigation systems waste water by atomizing it so that much of it is evaporates before it even reaches the ground- especially on hot or windy days. Install drip irrigators instead, and completely cover them with mulch. In this way virtually no water will be lost to evaporation, but monitor water flow and timing to ensure water isn’t wasted as runoff.

Surface irrigation is another wise way to water. Porous pipes, such as “Aquapore” may be laid in the soil to provide a gentle, steady flow of water. If you use an automated irrigation system you can install a moisture detector in the soil. If the soil is already wet (such as after rain) the detector will not allow the irrigation to be switched on. Any irrigation system connected to the mains water must be connected by a licensed / registered plumber and include a backflow prevention valve.

Tool For the Job

• Local plant information, camera
• Tape measure, pegs, string lines
• Spade, fork, barrow, garden trowel
• Secateurs, shears, hedge trimmers, pruning saw
• Watering can

Material Checklist

• Garden edging
• Top soil, clay breaker, wetting agent, pH adjuster
• Potting mix
• Mulch, compost, compost in
• Trellis
• Garden ties
• Hose and fittings
• Irrigation pipe, drippers, tap fittings
• Water tank, pip and fittings
• Plant stakes
• Paving stones
• Sleepers and spikes
• Fertilisers
• Plants
• Seeds

There can be a range of variables in your materials so it is best to check with a helpful Mitre 10 staff member who will give you the best possible advice.

For a detailed MitrePlan on “Watersaver Garden” follow the link or pick one up at your local Mitre 10 store. 
www.mitre10.com.au