Water and your garden

Save water in your garden by choosing plants that need less water  and using mulch to protect them.

You can water your garden efficiently by:

• setting up irrigation systems
• watering in the early morning or late afternoon
• mulching and composting
• using greywater
• storing rainwater in tanks
• building a rain garden.

You can also help water absorb into the ground by digging or aerating the soil to a depth of 250mm and incorporating decomposed organic matter.

Our Plant Selector Tool can help you find the right plant or tree for any spot. Find out more about choosing trees and plants.

Watering your garden

Each part of your garden may need different amounts of water. A garden’s water needs are determined by:

• soil type (clay soil makes water slow to absorb, while sandy loam soil absorbs water more easily)
• sloped areas, which can affect water run off
• plant types and where you put them
• microclimate, which is affected by buildings, walls, fences, hard surfaces, shade and windbreaks.

Water needs to get into the root zone. You can test this using cyclic watering:

• water an area until pooling or runoff begins, then turn the water off
• wait for the water to soak into the soil, then repeat
• in between cycles, dig down to see how far the water goes into the soil
• repeat the cycle until the water reaches the root zone (about 300 mm).

Many gardeners use a combination of watering methods, including fixed and drip irrigation systems, hand-held hoses and watering cans. Lawns are best watered using high pressure pop-up sprinkler systems.

Fixed irrigation

Fixed irrigation systems are the most time and water efficient. Get advice from a local hardware or irrigation store when installing your own automatic system. Keep in mind:

• your system needs to meet any local regulations
• separate garden beds, vegetable gardens or lawn areas into zones based on their watering requirements
• you may need an electronic controller
• you can use soil or rain sensors that override electronic controllers so you only water when the garden needs it
• you can override the system to avoid watering after rain.

Drip irrigation

A well-designed system can save water. Water can flow at low volumes and low pressure. It goes directly to the soil surface, limiting evaporation and wind drift.

Keep in mind:

• drip systems are best if designed and installed to be site and soil specific
• check regularly for evenness of watering, blockages and leaks.

Mulch and compost

Mulch protects your soil and allows water to penetrate. Mulch helps to conserve water, keeps weeds at bay and keeps the soil cool in summer. It slows run-off, reduces erosion and can improve soil quality.

Organic mulches are the most popular because they can improve the soil structure and add nutrients as they decompose. The best organic mulches are made up of coarse material that allows rain and irrigation water to penetrate through to the soil. Organic mulch can be:

• composted and aged manure
• fresh grass clippings
• fallen leaves
• sugar cane mulch
• tea tree mulch
• lucerne hay
• straw
• wood chips and tree bark
• composted horticultural bark
• shredded newspaper
• groundcover plants as ‘living mulch’.

Inorganic mulches such as gravel, scoria, pebbles and crushed rock are non-flammable and useful to minimise fire risk against your house.

Remove weeds from your mulch regularly. Spread mulch evenly to a depth of 75mm and keep mulch away from the plant stems to avoid collar rot.

Find out more about creating your own compost.

Greywater

Greywater is used household water from baths, showers, bathroom sinks and laundries. (Wastewater from toilets is called 'blackwater'.)

You can reuse greywater from your bathroom or laundry to water your garden. Generally, washing machine rinse-cycle water and bathroom water are the most suitable sources of greywater for garden watering. If you use low-salt, phosphorus-free detergents you do not need to restrict the use of washing machine water to the rinse cycle. However, laundry water from soiled nappies or wash water from domestic animals should not be used.

You can divert greywater from your laundry or bathroom directly to your garden or lawn by:

• using a bucket or siphon
• connecting the washing machine discharge hose to a diversion hose leading to the garden (check your washing machine suitability and instructions first)
• fitting the laundry tub waste pipe with an approved hand-operated diversion valve, which must carry a 'Watermark' approval and be installed by a licensed plumber
• fitting an approved diversion valve into the bathroom waste pipe by a licensed plumber.

Do not distribute greywater with a domestic garden hose that is used for other purposes.

Storing greywater

Store untreated greywater for no longer than 24 hours.

Treating greywater

Diversion devices direct greywater from the laundry or bathroom to the garden for immediate use without making changes to its quality. The greywater is not stored.

Treatment systems improve the quality of the wastewater by filtering, disinfecting and treating it. Greywater treatment systems need regular maintenance, such as cleaning or replacing of filters and periodic de-sludging of the holding tanks.

Talk to a licensed plumber before you install a treatment system or diversion valves.

Rainwater tanks

There are a lot of ways to store and use rainwater. When you install a rainwater tank, it can be standalone or plumbed into your house.

The simplest rainwater tank connects to your downpipes and is used only for watering your garden. You might also need a pump to provide the pressure for irrigation systems.

You’ll get maximum benefit when you install a plumbed rainwater tank. The water can then be used for toilet flushing and clothes washing as well as watering your garden. And you can make some savings on your water bill if you use rainwater instead of mains water.

Get advice from a licensed plumber or electrician.

Rain gardens

Well-kept rain gardens help filter storm water on urban streets. They take in excess water and store it underground.

Bio-filtration removes pollutants from water before it enters lakes and ponds.

If you have a rain garden on your street, hand pull the weeds and don't use any chemicals. This keeps the garden clear of debris, including litter, grass clippings and other organic material. Then stormwater can be filtered as it passes through the soil profile.

There are a range of plants suitable for rain gardens, and a variety of potential water sources.

Read more about rain gardens on ACT streets.

Watering trees efficiently

In dry weather, it's a good idea to water trees on your property and nature strip.

For young trees, an 8-litre bucket once a week may be enough. Trees taller than 5m may need several buckets.

Water trees in the morning or evening when it's cooler. Slowly pour the water under the tree, close to the trunk.