Severe droughts and water restrictions are a sobering experience for us all as we realise that good clean water is one of our most precious resources and its supply is not automatic. It is inevitable that we must all take stock and realise that water will start to cost us more and more in future. Any sane person will recognise that we must collectively reduce consumption and the garden is often a place where huge reductions in water usage are possible.
To begin with, it is crucial to recognise that plants will tend to adapt to whatever level of water they receive. If plants receive a lot of water they will tend to become lush and soft as new growth is stimulated. Conversely, if watered less they will adapt by reducing growth and going into more of a ‘survival’ mode.
The key point with watering is that plenty of natural rainfall will stimulate lots of growth, but if that rain does not fall then we can cut back on artificial watering and simply accept the fact that we will not get the same luxuriant growth. Your plants may not grow as fast or flower quite as profusely, but they will still survive. Just ensure that if the plants have been receiving luxury levels of water that they are weaned of that over a period of a couple of months otherwise they will wilt suddenly and possibly irreversibly.
It should also be pointed out that some plants such as succulents and leathery-leafed Australian plants (such as bottlebrush, grevillea and many others) are able to shut down much more efficiently than those that have lots of soft, large leaves such as those from rainforest environments. Therefore, if you really want to drought-proof your garden then go for a design theme that emphasises such plants. Not only will you save water, but the similar foliage types will give your design that certain harmony of appearance as well.
Another way in which we can help is through recycling water wherever feasible. A rainwater tank is the most obvious way to recycle water that would otherwise be wasted. Here is now a wide variety of choices when it comes to tank sizes and shapes such that they are much more compatible for modern urban areas than the traditional round corrugated iron jobs.
How do I use grey water in the garden?
‘Grey’ water from laundry and bathtubs is problematic, as health authorities warn that if left untreated it can contain human pathogens and therefore be a health risk. If you wish to pursue this option then seek advice from your local council or health authority about a suitable treatment system. A general rule is that grey water can be used on the garden, as long as it isn’t left to stand around in containers. Bucketed straight away to the garden is generally OK. Be aware that most detergents aren’t good for the garden, so it is generally best to only use the rinsing water from the laundry. Sodium based detergents, which are often the low phosphate ones, are the most harmful.
Tips for waterwise gardening
A couple of simple but often overlooked ideas include keeping a jug next to the kitchen sink and collecting the water that is usually wasted while waiting for the hot tap to warm up. This is a very convenient way of watering any nearby pot plants. Similarly, do not waste the water left over after boiling vegetables as it will also provide a little boost of nutrients as well as moisture for your pot plants and will keep them thriving.
How can I make my garden soil store more water?
As well as water that is wasted before it can even get to the garden we can make a lot more of the water that is delivered to the garden. Improving the water storing capacity of your soil or potting mix is simple and very effective. Well rotted organic matter such as peat or sphagnum moss, coir (coconut) fibre and home made compost can all be forked into your topsoil. Water storing crystals are another effective product that can be incorporated in soils or potting mixes to act as a sponge in storing extra water then gradually releasing it to your plants.
How do I mulch my garden to save water?
As well as storing moisture you can help prevent it from evaporating from your soil by applying mulch to the top of your soil. Mulches act as an insulating blanket and to be most effective they need to trap lots of air so choose one that has large particle size such as pine bark nuggets, coarse eucalypt chips or big chunky gravel. For maximum benefit in conserving moisture and stopping weed growth it needs to be 10cm deep, however, any depth of mulch will be better than none at all.
Another source of water wastage in the garden is spray irrigation. Sprinklers and even hosing water onto plants often leads to surface runoff and evaporation if we apply water faster than the soil can absorb it. The alternative lies in drip irrigation and there are many do-it-yourself systems available for watering not only garden beds, but also for potted plants. It is important to seek expert advice when installing any irrigation system, particularly if it is to be a permanent fixture.