Practical design in waterwise gardening should incorporate:
- the layout of the garden and entertainment areas
- the need for lawn areas — less lawn means less maintenance
Install a suitable irrigation system to suit your needs, and possible water restrictions. If you've got an existing garden, you can reduce the amount of lawn by converting it into mulched garden beds, increasing the amount of paved areas, or by using rocks and gravel.
Consider installing rainwater tanks and greywater recycling systems for use in your garden.
Canberra has poor soil quality in most areas, with high levels of clay and silt and low levels of organic matter. This means the soil becomes easily compacted, is hard to work and has poor drainage. This type of soil will hold water for longer but can only absorb around 3–8mm of water per hour, as opposed to loam and sand soild which can absorb up to 25mm per hour.
Clay soils make dripper systems the ideal choice for irrigating your garden. To improve soil quality and drainage, add organic material such as compost, aged manure and/or aged sawdust. Digging in a layer of sandy loam or applying gypsum dressing will also help loosen up clay-based soil.
Select plants that tolerate dry conditions. But remember that plants will only be drought resistant after they have established a good root system. It’s important to feed and water new plants until they are established.
When planting your waterwise garden, group plants together according to their water use. Put high water-use plants together in a low or wet part of the garden to make the best use of drainage. And choose your plants with a purpose in mind, such as shade, privacy, produce or aesthetics.
View the drought tolerant plants PDF for some plants suitable for water saving. You can also use the ACT Government 'think water act water' plant selector tool to further assist in your waterwise garden plant selection.
The smaller your lawn area, the less water you will need to use to keep it healthy. Plan your lawn areas carefully to balance recreational needs and landscape presentation.
As well considering lawn size when designing your garden, you can also choose grass types which require less watering. Some turf varieties are better suited to Canberra's climate than others. Experts recommend using a warm season, drought tolerant turf variety such as Couch or Soft Leaf Buffalo. These types of turf require much less water than cool season varieties and are available locally at nurseries and garden centres as seed packets or turf.
When using couch grass turf adjacent to garden beds ensure that a mowing strip 150–200mm deep be installed to prevent the grass sub-surface runners crossing into the garden beds.
When and how long you should water your garden will depend on the soil type, type of plants and possible water restrictions. You should water deeply and pick the times of the day when it's cooler, such as early in the morning, in the evening or overnight.
A cyclical watering pattern is recommended. Ideally you should water your garden for 10–15 minutes. Leave it for a couple of hours and then water again for 10 minutes. The frequency of watering should be determined by rainfall pattern. Avoid watering in strong winds and use a tap-timer for consistent watering times. Of course if water restrictions are in place, any watering must comply with the restrictions.
It can also help to divide your garden into zones. Water one section at a time once a week. You may think that this will be insufficient, but by doing so you are training your garden to use less water and adapt to the conditions.
When watering, water the base of the plant or shrub, not the leaves. And remember, don’t water for a week after good rain.
There are many benefits to using mulch. It reduces evaporation and runoff, suppresses weed growth and keeps soil cool in summer. Using mulch also allows better water penetration and creates an attractive landscape. The most commonly used mulches are:
- pine bark or mulch
- woodchips or wood shavings
- pea straw
- compost
- manure
- leaves or forest litter, and
- inorganic material like gravel or pebbles.
The best time to apply mulch is annual during spring. Before you apply it, prepare the ground by weeding, breaking up the soil and watering thoroughly. You should lay mulch 75–100mm deep and keep it away from plant stems to avoid collar rot. Don't use black plastic to stop weed growth as it prevents soil aeration.
Water the base of the plant and not the mulched soil.
Wetting agents
When applied to soil, wetting agents slowly release water into the plant’s root system. To ensure that the wetting agent works effetively , mix it well into the soil before applying mulch or compost.
Wetting agents can be used at any time during the year and are available in a liquid or granulated form.
Once your waterwise garden is complete, you need to maintain it properly. Weeding, pruning, and following the previously recommended watering practices will help you reduce water demand for your garden. And it will keep it looking as good as it did the day it was finished.