Watering and Grey Water Use

Gwen Elliot

(Note: This article was originally titled "Epacris in the garden - Watering and Grey Water Use" when it was published in the newsletter of ASGAP's Epacris Study Group. However, the information is of wider application to Australian native plants generally).

Most Epacris have very fine roots which do need regular moisture to sustain them, without the soil being waterlogged.

We are all now very aware of the need to use water wisely and generally Australian gardeners have discovered that we do not need to use as much water in the garden as was done in previous years. There are various ways in which we can assist our plants to survive and even thrive without regular supplementary watering.

How to Water

While some methods of watering including tall erect sprinklers are extremely wasteful, often distributing water also on pathways and into gutters, there are other much more efficient alternatives which can be used. Soaker hoses and trickle irrigation systems are two excellent means of water application. Direct the water ONLY where it is needed.

Watering with a hand-held hose or watering can will also allow you to see just where the water is needed.

When to Water

The first main consideration is that we should only provide supplementary watering to a garden when it is needed by the plants. Because we are permitted to water for a certain number of hours on a specific day, that does NOT mean that our plants will benefit from being watered then. Poke a finger into the soil to see if it is dry. Have a good look at the foliage and you will usually be able to observe whether all is well, or if the plant needs a drink.

Water only in the early morning or in the evening, to allow the plant to take in the moisture and reduce evaporation.

Availability of Water

Ensuring that all available rainwater which falls in your garden stays in your garden is one of the easiest and most successful methods of garden watering.

It is often possible with just some minimum contouring of garden beds and pathways to make sure that rainwater does not quickly run off into drains or neighbouring properties, but is held in swales, channels or even ponds so that it can be more gradually absorbed by the soil and the plants.

There is now an extremely wide range of water tanks and storage facilities available for domestic use, from upright metal and fibreglass tanks which can store several thousand litres, to slimline tanks for narrow spaces, or horizontal tanks and bladders for storing water under decking, steps, or even under the house.

Most municipalities now encourage the collection of water from roofs and this can certainly be a real bonus for garden watering.

Aids to Water Retention

Mulches are an important asset in regard to water conservation and minimising evaporation from garden soils. This aspect has been coverered in previous articles (see for example, "Mulches Aren't Just Mulches" and "Mulch and Native Plants".

Water-retaining liquids and granules such as EcoWet and Saturaid can also be very helpful in assisting water penetration into garden soils, while products like Rainsaver Water Storing Crystals will absorb the water then gradually release it into the soil later.

Grey Water from the House

Water which is collected while waiting for the shower to become warm can be collected in a bucket and used in the garden when next it is needed.

Grey-water from baths or the laundry should not be stored, but should be used in the garden within 24 hours. Grey water is not recommended for use on edible herbs and vegetables, but is generally fine for ornamental plants including Epacris. It is recommended that grey water be distributed around several different areas of the garden rather than using it regularly for the same plants.

The choice of soaps and laundry detergents is of paramount importance if grey water is to be used in the garden. We should avoid products containing high levels of phosphorus and sodium, and there are a number of these now available. Further information and an evaluation of products can be found on the website of Lanfax Laboratories, Armidale New South Wales, although there are some excellent products introduced in recent years which are yet to appear on this website.

From the newsletter of ASGAP's Epacris Study Group, March 2008.

Australian Plants online - 2008
Association of Societies for Growing Australian Plants