Every garden and lawn is different – from the plants you have chosen, to the soil you have and the wind and sunshine your garden receives. It is likely that different parts of your garden will have a different microclimate and may therefore have different watering requirements.
Planning your garden
When planning a new irrigation system or modifying an existing system you should select the system and emitters which are efficient and appropriate for your:
- soil type of your garden
- plant selection
For example, drippers are an excellent and water-wise irrigation option for most gardens, but may not be suitable for sandy soils.
The brochure Your Guide to Efficient Irrigation explains requirements for efficient garden irrigation equipment such as sprinklers and emitters, where efficient irrigation guidelines apply and offers gardening and watering tips.
Contact council on 131 872 for a copy of the brochure.
You should consult your local irrigation professionals, horticultural specialist or nursery to determine which system(s) are right for your garden. Your irrigation specialist may design a different type of system for different parts of your garden. Your emitters should be planned and placed appropriately in order to water effectively. Take a simple plan of your garden along to your local retailer or irrigation specialist so that they can help you design a system which will distribute the right amount of water in the right places.
Know your soil type
Different soils retain different volumes of moisture as demonstrated in the table below.
|Water (mm stored in 20cm depth of soil)||12mm||42mm||28mm|
If you have sandy soil, you will know that it retains relatively little water and therefore plants growing in sandy soils are likely to require more water to survive. However, applying more than 12 mm of water on sandy soil at a time is a waste of water, because it will simply drain through, past the root zone.
You should consult your local horticultural specialist about how to improve sandy or poorer soils.
Some tips and options include:
- replacing the soil with better quality loam
- treating the soil with a wetting agent or using water crystals
- adding organic matter such as compost
- using plants which thrive in sandy soils, such as coastal plants and some Australian native plants
If you are still unsure of your soil type or how to improve it, take a sample along to your local nursery or landscaping specialist and seek advice. Also, ask about the water retention properties of potting mix next time you’re buying it as there are significant differences between products.
Mulch your garden
Mulch is excellent for your garden. Common types of mulch include woodchips, straw, shredded plant materials and pebbles. A minimum depth of 5 cm and even coverage is required. A greater depth may be required to reduce evaporation effectively in your garden. This depends on the type of mulch used. Check with your horticultural specialist or nursery for more information. If you use organic mulch which breaks down quickly, top it up several times a year.
Drip-line systems are designed to sit beneath mulch or in the soil to reduce evaporation and ensure more water goes directly into the soil and to plant roots. Ask your irrigation professional or retailer for more advice on how to use these systems effectively when using mulch.
Council's brochure Waterwise Gardening includes information about the benefits of mulching, types of mulch and which mulch to use. The brochure also includes information on composting, worm farming and greywater. Contact council on 131 872 for a copy of the brochure.
Choosing the right plants
If you are re-planting or planning a new garden, you should choose plants which have a low water requirement and are likely to thrive in the specific conditions in your garden such as exposure to sun, wind and soil type. Remember, it is a good idea to group plants which have similar watering requirements, so that you can irrigate more effectively. Your local horticultural specialist or nursery can assist you in selecting the plants that are right for you and your local area.
The Plant Guide brochure includes information on planting techniques, a checklist to take to your plant nursery, and a large list of plants with their preferred growing conditions. Contact council on 131 872 for a copy of the brochure.
The depth and quality of soil beneath your lawn dramatically influences the water retention properties of your lawn and its’ ability to withstand dry periods. The Queensland Turf Producer’s Association recommend a minimum depth of 100mm of quality soil underlay meeting the Australian Standards for landscaping and garden use AS 4419-2003. The make-up of the underlay should consist of:
- Quality loam with sand, silt and clay components
- Organic matter/ humus
Ask your accredited turf supplier for more information on how to achieve a water-smart soil underlay. If your existing lawn has been laid on rubble or other poor quality materials, it will not thrive in the longer-term, particularly in times of drought. It may be best in these circumstances to re-lay turf after a suitable underlay has been prepared.
When relying on builders or landscape contractors to plant a new lawn, you should make sure they comply with the Guideline by using quality underlay of a minimum depth of 100mm. Add organic matter or wetting agents to your lawn after planting to improve its’ soil retention properties.
Choose water efficient turf varieties
When planting a lawn for the first time, make sure you choose a warm-season variety. There are a variety of commercially-available grasses belonging to the grass species below which can be grown under a range of conditions. These species are well-suited to the SEQ climate and use significantly less water than other grasses:
- Buffalo grass
- Couch grass
- Zoysia grass
Ask your accredited turf supplier to recommend a water-efficient variety to suit your property.
Maintaining a water-smart lawn
Now that you have laid your new water-efficient lawn species on a suitable underlay, you should ensure your lawn is maintained in a water efficient manner. Only water your new lawn when it actually needs watering and in the periods and on the days permitted in the water restrictions. This will ensure your lawn can cope with dry conditions.
Signs that your lawn is ready for watering include:
- changing colour
- the soil below is difficult to penetrate using a sharp object
- your lawn doesn’t spring back after being walked on
A water-smart lawn requires very little water to maintain it in good condition – up to only 6mm per day in summer and 3mm in winter. This would be achieved on most lawn areas with no more than an hour of watering per week with an efficient sprinkler or irrigation system. With rainfall, this would be much less. Unlike many plants, lawn can remain dormant for some time during periods of drought and quickly spring back to life after rain.
If you observe bright green patches or the presence of fungus (toadstools) or moss, you may be over-watering. By watching your lawn, you will soon get a feel for how often and when you need to water throughout the year. Do not water your lawn during winter as your lawn is dormant during this period.
If you have a large area of lawn to be irrigated consider installing an efficient irrigation system designed to water the entire area evenly. Attempting to move an efficient sprinkler around a large area may result in areas of overlap (soaked lawn) and dry patches.
Improve the water-penetration properties of your soil by regular aerating and applying organic material or wetting agents so that more water reaches lawn roots.
Apply fertiliser during the spring and summer months when there is higher rainfall and your lawn is actively growing. Use small amounts of an organic fertiliser as this will require far less water post-application than a chemical fertiliser.
Mowing your lawn incorrectly will result in it quickly drying out and needing more water. When mowing your lawn you should:
- Keep your lawn at a height of at least 3cm and only cut when necessary; and
- Mow outside of the heat of the day when your newly cut lawn will simply dry out.