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(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!