(first published July 2008, updated April 2009)

It's wonderful to have a garden and add a splash of green in an urban environment; but our gardens tend to consume massive amounts of water; something that's becoming an increasingly scarce resource in many parts of the world.

Irrigation accounts for the bulk of water use in homes, particularly in drier areas over the summer months. A few of the biggest mistakes made are:

a) Plant selection; usually by using plants that aren't native to the area
b) Sprinklers that throw water up into the air, which is then windblown or evaporates
c) Watering during the hottest part of the day
d) Over-watering

Here's some tips for reducing your garden watering footprint - and to save some money on water rates at the same time.

Plant selection

When you're next shopping for plants for your garden, consider not only your area's current rainfall, but what's projected for the future. In many regions of the world, rainfall is dropping; so a plant that might get by fine now without additional watering may not do so in the future.

Sprinklers

Many sprinklers throw out fine droplets and on a hot day, these droplets simply evaporate. While your garden gets some water, much is lost. Look to buy a sprinkler that throws water closer to the ground in large drops

Drip irrigation

This can save you a ton of water. Drip irrigation (aka  trickle irrigation or micro-irrigation) consists of a series of pipes with drippers hanging off them that deliver water directly to where it's needed. Given the targeted nature of the delivery, far less water has to be used.  Using a special piercing device on the main pipe, you can attach drippers exactly where you need them and you can plug the hole at a later date if need be. The equipment is simple, easily scalable, pretty cheap and durable and can be purchased at most hardware stores and nurseries.

Tip: when using drip irrigation, you'll need to check the drippers regularly as they can get clogged with water-borne particles, particularly when used with a greywater or blackwater recycling system. Birds also have a tendency to move the dripper hoses as they forage.

Irrigation timers

If you use an irrigation timer, set it to run half the normal time, but run it a second cycle a minimum of half an hour later. This will dramatically reduce runoff. 

Check your equipment

Check over your hose and sprinkler connections for leaks - a drop wasted each second can add up to a couple of gallons each day. Also check the heads of your sprinklers are clear for maximum effectiveness. 

Watering time

The best time of the day to water is either just on sunrise or just on sunset, as this minimizes water evaporation

Make use of old soda bottles

Richelle D. contributed this tip: "I have several 3 liter bottles, filled with water and pushed upside down into the ground to water my outdoor trees.  The soil draws the water from the 2 liter bottle or even gallon jugs when dry."

Mulch, mulch, mulch

Mulching is adding layers of plant material such peastraw or bark to keep the sun off the soil and therefore retain water. Mulching is one of the most effective ways to reduce water needed in a garden - up to 50%. Mulch has the added benefit of preventing weed growth, deters pests, helps to stabilize soil temperature and provide nutrients to the soil as the mulch decomposes.

User fertilizer sparingly

Try to avoid using high nitrogen fertilizers during dry conditions as they will encourage growth and your plants will need more water.

Aerate your lawn and garden

Aerating tools can be purchased at most hardware stores for around $50. An aerator pulls out small plugs of soil allowing air and water to penetrate deeper. Deeper moisture means deeper root systems; which makes plants more resistant to dry spells and requiring less water.

Make trees a watering priority

Grass may die, but it grows back quickly, whereas a tree may take decades to grow. Trees also provide protection from the harsh sun for other plants and can reduce ground temperatures in a garden substantially. If you have to choose between watering your lawn and watering your trees; prioritize the latter.

Consider a rainwater tank

Given the amount of water gardens require; consider adding a rainwater catchment system to your property - it can help act as added insurance for a reasonable supply of water during the dry months or when your local authorities introduce restrictions.

There's all sorts of rain water tanks and barrels available to suit your premises, ranging from holding a few dozen gallons, to thousands.

Rainwater catchment formula

So much water is wasted through not harvesting rainfall. To get an idea of how much water you're missing out on, use these simple rain water catchment formulas:

Metric:

1mm of rain on 1 square meter of roof equals 1 litre of water

Imperial:

Roof square feet multiplied .6 for every inch of rain = gallons

By the way, many local governments now offer incentives and rebates if you install a water tank, so check with your local council for any programs they may have in place.

Recycling household water

Just as water is wasted outside the house, so it is inside. Thousands upon thousands of gallons go down our drains each year from the the washing machine, shower, sink and toilet. You can do simple things like:

- putting a bucket in the shower
- run a hose from your washing machine outlet to the garden (if it's not uphill)

.. or you can opt to spend a bit of money and get a greywater or blackwater recycling system installed. We had a blackwater recycling system in our last house and it was fantastic - I greatly miss having it.

Do you have some tips for saving water in the garden you'd like to share? Please add them below!