Episode: VIC Waterwise Special ? Our Changing Climate
Presenter: Melissa King

Soil types vary considerably across Melbourne and Victoria. From the deep friable red loamy soils found in the rolling country between Silvan and Monbulk to the deep, nutrient poor sands in areas from Black Rock to Brighton, and along the coast of Port Phillip Bay.

Then there are those heavy clays with just a thin layer of loamy topsoil which occur extensively in the north-west of Melbourne. Plus everything in between.

When it comes to creating a successful, water wise garden one of best places to start is at ground level. The type of soil that you have got can have an enormous influence on the plants you can grow and your approach to gardening and conserving water.

In Blackwood, the Garden of St Erth is where you will find the kind of hard clay that you would expect from a former gold mining site. Clay soils can be challenging. When they are wet they can become quite sticky, and in winter some are at risk of holding too much water so they become a slippery mess.

On the other hand, the summers are long and dry and when clay bakes in the sun it can form a surface crust that is almost impenetrable to water. Clays are also easily compacted.

You can condition clay soils by adding masses of organic matter like compost and well-rotted manures to improve soil structure and help retain moisture and nutrients. Organic matter also adds lots of beneficial microbes to the soil.

The other magic ingredient is Gypsum Clay Breaker. It is a soil conditioner which improves the structure of clay soil so it changes hard, compacted soil into an open workable soil that is more viable, with better water penetration and aeration, which are all important for good growth. Just dig up the clay soil, then spread 1-2 kg per square metre and water in well.

Water repellent soils all benefit from a wetting agent, which helps to break down the waxy surface on soils and ensure that the water you are applying gets down to the plant roots. You can also mix water storage crystals through the soil, they absorb water and swell to 100?s of times their own weight, providing a reservoir for plants to draw on in dry times.

The other way around tough clay soils, is to work with them and choose plants that will grow well in the conditions. Some great choices are the Japonica or Flowering Quince (Chaenomeles x superba) for sumptuous colour and a stunning hedge, Euphorbia (Euphorbia characias subsp. Wulfenii) is a real showstopper with masses of lime green heads or for foliage you cant go past Cardoons (Cynara cardunculus) with their architectural form and edible stems..

During the warmer months water deeply and infrequently to encourage roots to grow deep into the soil, improving their tolerance to drought.

Irrespective of how tough your soil is, with the right gardening practices and plant selection it is possible to create your own oasis.

Featured Location

Garden of St Erth
http://www.diggers.com.au/GardensStErth.htm

Featured Products

Yates Gypsum Clay Breaker

• Soil conditioner for improving the structure of hard clay soil
• Changes hard, compact soil and clay into open, workable soil.
• Increases water penetration and aeration by improving the soil structure.
• Aids drainage of wet soils, decreasing the risk of root rot.
• Easy to apply and effects last for several years.

Waterwise Water Storage Crystals

• When added to potting mix or garden soil, the crystals absorb up to 500 times their own weight in water.
• The water is released over a period of time as the plants require it.
• Reduce water usage and increase the times between watering.
• Effective for up to five years and biodegrade harmlessly.
• Prevents the soil from drying out, improves soil aeration and drainage.
• Potassium based.