If you understand your garden, it’s orientation, its soil and the climate, you will have a better chance of designing a healthy and sustainable landscape. You will be able to cater to the needs of plants, particularly light and water, while making sure you have the appropriate plants in each spot.
Know Your Climate
Melbourne’s climate can be quite variable – famously with four seasons in one day. If you want a healthy, sustainable garden, it’s worth being aware of the local climate. The good news is that in Melbourne, the temperate climate allows you to grow a great variety of plants. While winters can be cool, it rarely gets below freezing. Summers can have some very hot days but with plenty of milder ones to provide relief.
The main limiting factors are drought and frost in some areas. However there is plenty of scope to grow many plants from tropical zones as well as from cold temperate zones. It depends also on what part of Melbourne you are in. The western suburbs have a drier Mediterranean climate compared to the eastern suburbs. As you get closer to the Dandenongs, the climate is distinctly wetter and cooler.
Orientation of the Garden
Within your garden, you are likely to have a range of micro-climates. The orientation of your house and other structures create different conditions on your site. This will effect the availability of light, warmth and water for plants.
South Facing Garden
A south facing wall will collect the wettest weather and is more protected from the warmer drying winds and sun from the north. If you have any plants that are not drought tolerant and prefer a bit of shade, this is where they could be best cared for. If there is some wind protection here, it can be a great area for a tropical garden. Many of the plants you find being sold as indoor plants are adapted to these shady areas, so long as there is no frost.
Prostanthera lasianthos, also known as Coranderrk or Victorian Christmas tree, naturally grows as an understorey tree in the Dandenongs. Because it prefers a protected, shaded position, it is a good candidate for a south facing garden where it is happy to collect southerly moisture and avoid harsh sun.
West Facing Garden
In Melbourne, most of the weather comes from the west, including warm north westerlies and cool south westerlies. It is also the direction of harsh afternoon summer sun. This is where you will most likely want some protection. Taller buffering shrubs or trees that can screen the home from the more aggressive weather is a good idea.
Acacia dealbata, or Silver Wattle, grows naturally through most of the Melbourne suburbs. It is not only an attractive tree with its silvery foliage and creamy yellow flowers, it is very quick growing. Silver Banksia makes a very useful and rapidly growing screen where some protection is needed on the western side. It is happy to receive the weather that tends to come from the west.
North Facing Garden
The northern aspect is the most preferred orientation. This is where you would best have your windows looking out to the garden. The sun spends most of its time in the northern sky as it travels from east to west. In winter it stays low in the sky, so you want to maximise the amount of sunlight coming through from that direction. The trouble with that, of course, is that in summer you will want to reduce the heat and light from the sun. This can be achieved by having eaves just deep enough to shade the high summer sun but not the low winter sun. Also using deciduous trees and climbers will provide a leafy canopy in summer while giving you a clear sky in winter.
Lagerstroemia indica or Crepe Myrtle is a small deciduous tree that provides lots of interest through the year with its summer flowers and autumn foliage. It will provide a shady canopy in the warmer months while allowing welcome winter sunshine through the leafless limbs.
East Facing Garden
An east facing garden suits many plants that enjoy the milder morning sun but resent the afternoon heat during summer. The danger is that because most of our weather comes from the west, the east side can miss out on getting adequate natural rainfall. So, it’s worth just keeping an eye on an east facing garden to make sure it doesn’t get too dry, particularly if it is beneath the eaves of the house. Growing dry tolerant plants here would be wise.
Wake up to the birds on the eastern side of your house with a Banksia marginata or Silver Banksia. It is an indigenous small tree through much of Melbourne and is ideal for attracting native birds to its nectar rich flowers. It is drought tolerant and provides some protection from morning summer sun.
Know Your Garden Soil
At least half of your plants exist underground. This is where the plants’ roots are getting hold of water, oxygen and minerals, so it’s crucial that the soil is in a good, healthy state. It is critical to be aware that plants need to breathe oxygen through their roots. This is illustrated by the way so many plant deaths are the result of over watering. A plant can literally drown if it is too often watered when it is looking stressed. Soils will generally range from light sandy soils to heavy clay soils. Each of these types will provide different availability of air and water.
Types of Garden Soil
One of the factors of a healthy soil is its structure. If it is very coarse and sandy, it’s great for drainage but water can go through it too quickly. Good drainage provides plenty of air in the soil for the roots to breathe. Clay soil on the other hand, is better at holding on to water but this can also be excessive and lead to poor drainage. Also, in drought conditions the soil becomes like a solid brick.
An ideal soil is a soft crumbly loam that gets the water holding/draining balance right. The best way to achieve that is with the inclusion of organic matter. This can be in the form of compost or manures and can be worked into the soil. This not only provides better access for water but encourages more soil organisms which in turn improves the soil’s health. It will allow some water to remain in the soil without getting soggy.
Mulching is also an important method of keeping moisture in the soil and keeping it healthy. A 7.5 cm layer of material like bark chips or stones and pebbles let water through and reduce soil evaporation. Organic mulches also encourage those good soil bugs again. Plastic sheeting is not as good as it reduces access of water and organisms.
And don’t forget some sensible irrigation. Setting up some drip irrigation hose around the garden which is placed under the mulch layer will bring water directly to your plants with minimal water use or waste. It’s also an easy time efficient way of watering the garden.
Once you’ve got the right plants in the right spots, you’re paying attention to the soil and making watering easy and effective; summer garden devastation should be a very unusual event.