Save the World with a Garden Sprinkler

Resources are the buzz word of our times. We’ve used most of them up, apparently, and we don’t know where we’re going to get any more. We also have a fluctuating and extremely unpredictable weather pattern, which delivers oodles of rain one year and virtually none the next – playing havoc with the water table and making the irrigation of our gardens a constant and annoying problem. Fortunately for the resource conscious gardener, a whole new world of garden sprinkler kits is now available at extremely reasonable prices (allowing us to husband that other fading resource, money) – ensuring that the grass stays green while the planet doesn’t suffer. Saving the world really is this easy: turn the tap on, turn it off again. And watch as a scientifically measured quantity of water is delivered to all the right places.

Here’s the thing about the way garden watering used to be (and still is, for the terminally unhip): it uses way more water than the plants or grass actually need. If water is delivered efficiently and well, it can be done so in far smaller quantities than one would imagine – in the case of plants, for example, one only needs a few well placed drops; while for a lawn it’s all a matter of getting an even coverage.

That’s not as easy as you might think: a garden sprinkler naturally has more force and a higher concentration of water at its exit points (i.e. the nozzle mouths where the water is ejected before falling on the garden) – and less at the edge of its range. Modern sprinklers combat this uneven coverage in two rather ingenious ways: either by refining the spray itself, or twisting the direction of the water as it travels through the air. Here’s how.

When the garden sprinkler simply emits a fan of water, which is sprayed across a lawn in a slowly moving curtain, there is a more concentrated area of water at the “base” of that fan than there is at its edges. In order to ensure a more even coverage the nozzles of the sprinkler “split” the water and expel it in tiny droplets with waxing and waning bursts of force – which gives a huge surface area for a smaller quantity of water and allows the finest mist to fall on all areas of the garden. More surface area, as any physicist will explain, equals more efficiency: more of the volume of water is used by the plants than it would be if the drops were larger.

The other way of achieving the same effect is with a garden sprinkler that rotates, while spraying water up and out. The rotary motion of the nozzle arm causes twisting sheets of water to fly across the garden: which, for every rotation, delivers a much greater average coverage than one gets by simply spraying back and forth.

Either way, the sprinkler has come on in leaps and bounds since it first replaced the garden hose in the 1980s. A modern garden sprinkler is capable of delivering precisely calibrated quantities of useful water across any area of grass – ensuring that the drain on one of our planet’s most precious resources is as small as possible.