the new garden
The steps for rebuilding a garden are essentially the same as if you were creating one from scratch.
1. Dream & plan
Plan big, then break it down. Consider your climate and microclimate, frost risk, watering capacity, your family, interests and lifestyle, and spend time on a vision for your garden. Create an overall plan, and break it down into small steps and achievable projects.
Make a wish list, then prioritise what you want to include in your garden. Do you want an entertaining area, fruit trees, a vegie patch, a herb garden? Perhaps lawn for the kids, grandkids or pets? What sort of plants do you want to grow? Productive plants, flowering plants, plants that provide colour and interest year-round, plants to attract birds and butterflies, flowers that you can pick and bring inside?
2. Know your climate
The climate here in South Australia is often described as Mediterranean, and is characterised by long, hot, dry summers; short, cold, wet winters; and a relatively brief spring and autumn (measured by the plant patterns, not the calendar month).
Plants in this climate are adapted to start growing with the first autumn rains; be in full growth, flowering and setting seed in winter and spring; and stop growing in summer unless supplementary water is given. The belief that gardens are dormant in winter is not true in this climate – despite deciduous trees losing their leaves, the rest of the garden, both above and below ground, is in full growth. This is evidenced by all the weeds that grow!
The ideal time to plant in my climate is autumn and winter, as it allows a number of months for a plant to settle in and become established before the next hot summer arrives. Optimum planting times vary between climates. Wherever you live, I suggest you throw away the calendar!
3. Create a microclimate
The secret to enjoying gardening in a hot, dry state such as South Australia (and, indeed, anywhere in the country) is to make the best of what we have by creating a special microclimate in our gardens, one that is favourable to life – plants, creatures and, most importantly, us!
To do this, create shade and shelter, reduce unnecessary hot, reflective, heat-absorbing surfaces – such as large areas of paving, brick walls, and tin fences and sheds – and add limited areas of appropriately placed lawn.
Shade from trees and vines makes a garden waterwise by cooling it and reducing evaporation. As breezes pass
through the shaded areas of a garden, those areas are cooled. It’s effectively a natural form of air conditioning for your home and surroundings.
If trees are deciduous, they provide shade in summer, and allow precious winter sun to shine through. They can be used to create passive solar heating and cooling in your home.
Shelter protects the garden from extremes. In South Australia, one of the most troublesome climatic conditions is the hot northerly winds. Gardens that are exposed to these winds have a much higher rate of evaporation than those that are protected. A combination of fencing and established windbreak, hedging or screening plants prevents the garden within from drying out as much, so it doesn’t require watering as frequently. This kind of shelter will take a couple of years to establish from scratch, but it’s worth it.
Lawn helps to cool the garden, which is why I’m a fan of having limited areas of appropriately placed, drought-tolerant lawn. Children and pets love having some lawn to play on, but lawn is also beneficial for adults, as walking barefoot on grass is an opportunity to be grounded and connected with nature, and this is increasingly important in the fast-paced, high-tech, often ‘low nature’ world that many people live in.
Siting a lawn on either the northern or western side of a building will keep a garden cooler than hard surfaces such as paving or concrete. These hard surfaces absorb the heat and act as ‘heat banks’, which means the temperature directly above them is far greater than the normal air temperature, and they continue to radiate heat when the sun has passed.
By understanding your soil and your site, and choosing the most appropriate variety of turf for your conditions, a lawn need not be a water guzzler, and you can use it to provide sustainable, affordable cooling for your home and garden.
If possible and practical, use greywater applied under the surface to water your lawn, as it’s a resource that is too good to waste. Turf is more tolerant of repeated, long-term greywater use than many other plants. (Look for more about greywater in the next issue of the magazine.)
4. Prepare for frost
As well as coping with the heat and dry, many of us in Australia need to plan for frost. When looking at a Bureau of Meteorology map of potential frost days per year, it’s clear that areas with greater frost potential are closely aligned with the areas in south-eastern Australia affected by the 2019–2020 bushfires.
The obvious solution for gardeners in frosty areas is to choose frost-tolerant plants, however, with the varying degrees of frost, a plant that survives frost to –2°C or –3°C may be killed by –5°C. Also, some plants are frost-hardy once established, but frost-tender when young.
You can cover plants at night when frost is expected, but this is time-consuming and often gets forgotten until it’s too late! Instead, use tree guards to provide some frost protection when plants are young, and treat your new, tender plants to applications of liquid seaweed and anti-transpirants. These two treatments should be applied monthly to susceptible plants in their first year when there is a risk of frost, and can give you 2–5 degrees of frost protection.
A combination of fencing and established windbreak, hedging or screening plants prevents the garden within from drying out as much. This kind of shelter will take a couple of years to establish from scratch, but it's worth it.
5. Work out water zones
With the frequency and severity of drought predicted to increase in Australia, designing your garden with water requirements in mind can save you money and heartache. You can do this by grouping plants with similar water requirements into zones. The ideal or optimal breakdown of the garden (which I use and often suggest) is 50 per cent no water use, 25 per cent low water use and 25 per cent high water use.
The zone for 50 per cent no water use is for plants that need no supplementary watering once established. Plant selection is critical, and plants may be indigenous, native or exotic varieties from comparable climates, matched to the conditions and microclimate of your garden. In extended drought, they may need supplementary irrigation, but this is only as required.
The zone for 25 per cent low water use is given a good soaking every week or so in summer, and could include fruit trees, roses and limited areas of lawn.
The zone for 25 per cent high water use requires watering more than once a week, and could include pot plants in a fernery or shadehouse, and in-ground vegie gardens.
6. Choose your plants
The three main groups of plants to add to your garden are:
Local indigenous plants These are obviously great choices because they grow naturally in your area.
Australian natives Choose varieties from comparable climates in the country. In southern Australia, avoid plants from tropical or subtropical climates, as they are used to summer rain and require regular watering throughout the dry summer.
Climate-compatible exotics In my climate, I look to plants from South Africa, western China, the Middle East, California, Mexico and Chile. Many have physical adaptations suitable for my climate and lack of water, such as summer dormancy, tough leathery or waxy leaves, succulent leaves, small needle-like leaves, silver-grey and hairy foliage, or swollen, water-storing roots, bulbs, rhizomes or trunks.
When considering plants that are exotic or from another part of Australia, avoid those with the potential to ‘jump the fence’ and become an environmental weed.
7. Set up the vegie patch
When planning a new vegie patch, choose a sunny site that is free from the root competition of trees and large shrubs. Ideally, select a spot that gets morning sun, and some protection from the fierce late-afternoon sun in summer. If you’re rebuilding a vegetable garden where the soil is already alkaline, scrape away any
At Sophie’s Patch, we use appropriate plant choices and our watering zones to reduce fire risk. We water plants near the house the most, keeping them lush and green, to act as a firebreak.
ash layer before working on improving the soil with organic matter.
If your soil is very heavy, the ideal site is impacted by tree roots, or you want to minimise bending over, grow your vegies in a raised bed. Raised beds can be done a few ways, but the two most popular types are made from hardwood sleepers or corrugated iron preformed tanks. If you go for a tank garden, choose heritage-grade galvanised iron. This resists corrosion from acids in the soil. Be aware, though, that corrugated iron beds can get too hot for many vegetables in summer, causing plants and fruit to become scorched, and roots to die. You may need to shade the sides of a metal raised bed for your vegetables to thrive.
As most vegetables have high water requirements in the warmer weather, consider making your vegie garden a wicking bed, which is self-watering and needs to have water added only every 7–10 days, depending on the conditions. You can see how I made one of these on Gardening Australia TV by looking on the website (abc.net.au/gardening), or in the April 2017 issue of the magazine.
If you’re purchasing soil to fill the bed, choose a good-quality blend suitable for growing vegetables. If using your own soil, improve it with lots of organic matter, as this affects the quality of your crops.
8. Mulch for success
Whether you’ve planted natives, exotics or vegetables, the last step is to mulch them. This is important after any planting, but especially where soil is affected by fire.
Mulching keeps moisture in the soil, and can reduce loss of water through surface evaporation by 70 per cent. It can also smother or suppress weeds, which not only look unsightly but also compete with your plants for moisture, nutrients, space and light and, if left to flourish, can outcompete many young plants.
A good layer of mulch reduces weed seed germination, as seeds that don’t touch the soil have less chance of germinating. Mulch insulates the soil, too, keeping it cooler in hot weather, which makes worms and soil microbes happy, and stops the plant roots from stressing. Another benefit of mulch is it slows the flow of water across the soil, increasing absorption and decreasing erosion and stormwater run-off.
There are four types of mulch, and the type that you select is a personal choice. The first is living mulch, such as groundcovers. Then there are bark-based mulches that stay around for one or two years, depending on the coarseness of the bark, and straw-based mulches, such as pea straw, that are usually preferred for vegetables because they break down in less than a year, adding extra organic matter to the soil. Finally, in areas with a high fire risk, you can use inorganic mulches, such as pebbles, crushed brick, gravel or scoria, which are nonflammable.
As a rule of thumb, apply mulch about 3–5cm thick on soils that are moist or well watered. The depth of the mulch depends on the type of mulch you use. Heavy bark mulch should not be applied as thickly as a light, straw-based mulch, which is full of air. If you don’t apply enough mulch, it won’t work, whereas too much will stop rainfall and irrigation penetrating into the soil and may even cause problems with collar rot on the plants.
This story is copyright ©Sophie Thomson, and is reproduced here with permission.