CAN GARDENS SURVIVE THE DROUGHT?
TRY THESE PROVEN METHODS TO BATTLE THE DRY TIMES.
THE current prolonged drought affecting the eastern half of our country has recently taken a turn for the worst in our local government region with the realisation that many groundwater sources, essential for supplying vital potable water to outlying towns and localities through council bores, are showing signs of stress due to a lack of inflow from rainfall.
The imposition of unworkable water restrictions on those wishing to maintain any semblance of a presentable garden has prompted many readers of this gardening page to ask what can be done to keep a garden alive in the face of this current crisis and future water shortages.
Whilst we can’t literally “drought-proof ” a garden if rain doesn’t fall and water supplies expire, there are many tips and tricks we can utilise to help gardens survive long enough for when good rains arrive, and the crisis is averted.
Firstly, let’s clear up a few misconceptions about plants and water use.
A “water-wise” garden does not have to consist of succulents, cacti, and native plants.
Once established, there are many exotic plants that can survive prolonged dry periods as well.
A lawn that has been carefully selected and maintained will use no more water than if the same area was planted with so called “drought-hardy” plants.
A thicker layer of mulch isn’t necessarily better for water retention – sometimes a thick, fine mulch can be water repellent when dry, and it can also stop up to 40-50mm of rainfall from getting to your soil!
So what needs to be done to reduce water usage in a garden but keep it looking acceptable and growing satisfactorily?
Firstly, and this is a MUST, gardeners need to know what type of soil in which they want to grow their plants.
If you’re dealing with a free-draining, open-textured sandy or loamy soil, then it should be improved with the addition of a quality compost or old manures.
This will help to hold more moisture and therefore more nutrients will be available to plants.
If you’ve wound up trying to work a heavy clay, then the best course of action is to add a quality compost or old manures as well, with the incorporation of gypsum on really heavy clays a must.
This will help to create a good structure through which water can percolate whilst being held in the right quantities for the longest possible time.
Even an “ideal” soil texture, such as a clay loam, will benefit from the addition of organic matter such as compost so that soil moisture is held for the maximum time for plant uptake.
The aim with all soil types is to ensure that the profile in which plant roots grow (for most plants this is down to about 30cm deep) will hold the right amount of moisture for the longest possible time.
A well-designed garden is also vital for helping plants survive the dry.
Make sure that prevailing winds, which can remove large amounts of moisture from soils due to evaporation, are slowed or redirected by plantings acting as windbreaks.
Raise garden beds and lower pathways, so that water will pond and soak into the surrounding soil or will be directed to parts of the garden where it’s needed in larger quantities.
Materials such as gravels and decomposed granite and sandstone are best for paths, as they allow water to soak into the surrounding garden, as opposed to solid materials such as concrete and pavers, which may shed water away from where it’s needed.
As for mulch, use “chunky” mulches such as pine barks or hardwood chips (over 20mm in size) to a maximum depth of 75mm (or three inches), as this will help to retain moisture, reduce weed growth, as well as maximising any rainfall entering the soil surface.
Avoid fine mulches which can pack down and exclude rainfall from your soil.
Enhance rainfall and irrigation infiltration by using soil wetting granules (NOT water crystals) over the entire garden (garden beds, lawns and pots).
Don’t over-fertilise, as this will result in soft, lush plants that will actually need more water to maintain their good looks, as well as making them more susceptible to pest and disease attack.
Alternate between synthetic and organic fertilisers.
Anecdotal evidence has shown that regular applications of seaweed products will help plants withstand stressful conditions such as cold, heat, frosts and droughts.
Irrigation during the establishment phase of plants, which can be for several years, is vital.
It’s best to install a drip irrigation system with some type of timing device to enable long, infrequent, deep waterings, rather than short bursts from hand-held sprays which encourages shallow, drought-tender root systems.
Not only do drip systems use up to 60% less water than sprinklers, they apply water directly to root zones. There’s no evaporation, no runoff, and don’t miss the target on windy days.
A well-maintained drip system will also be useful for the occasional but essential deep watering to keep mature plants alive in really hot, dry conditions.
Gardeners should also seriously consider installing tanks to collect precious rainwater, as well as utilising grey water from washing machines, sinks and showers.
What about plants? When purchasing, select healthy plants that are in proportion to the pots in which they are growing, and that show no signs of poor nutrition, pests, diseases, or being rootbound. Ask your local horticulturist about which plants will be suitable for your climate and region.