Irrigation for Landscaping & Gardens

Landscape & Garden Irrigation

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With summers becoming drier and our expectations of our amenity landscapes increasing, irrigation of landscaped gardens is becoming a very important subject. Gardens and lawns can be effectively irrigated using highly engineered sprinklers & drip systems. If you just want to water a little garden on the cheap, then go to your local hardware store. But if you want to professionally irrigate lawns and gardens (and for that matter shade houses, glasshouses, hanging baskets, hedges and borders) then read on.

Lawn Irrigation

It’s all about Uniformity:
Let’s start with the easy subject. There is a way a professional irrigation contractor will always tackle a lawn area which differs from how home gardeners will normally attempt it. Instead of the one sprinkler in the middle of the lawn, which tends to provide poor uniformity, overly dry and overly wet areas (which will show up as brown areas and sodden green areas), the irrigation professional will install part-circle lawn sprinklers around the perimeter of any given lawn. If the lawn is very wide then a few center pop-up sprinklers might be required, but generally the model of lawn sprinkler will be decided upon by the width of the lawn. Therefore if your lawn is 6 metres wide then we’d chose a sprinkler that throws 6 metres radius. If the lawn is 12 metres wide, we’d either choose a 12 metre radius sprinkler, or three 6 metre radius sprinklers; one each side of the lawn and one in the middle.

As a general guideline, the following sprinklers can be used for different sized lawns:

For each of these sprinklers there are a few models and nozzles to choose from. Generally this is dependant upon exactly how far you want the sprinkler to throw the water, and you’ll be able to determine this by looking on the sprinkler performance chart. Remember too that the specifications for any sprinkler are based on a completely still (no wind) environment. In reality it’s generally best to add 10-20% throw expectation to allow for environmental factors in the “real world”.

Garden Irrigation

Dripline:
Often the choice of professionals when irrigating gardens is to use Rainbird dripline. This is not the same as leaky hose, or drippers distributed randomly along a piece of irrigation tube. Dripline is a product used worldwide for irrigation of gardens, hedges and many horticultural crops. Vineyards in many countries use dripline to water their vines.
Dripline is normally installed on the surface of the garden and held in place us

ing dripline stakes, which we suggest you install every metre. Then if the garden is to have a mulch cover, this can be thrown onto and raked over the top of the dripline. This hides the dripline from view and means that when you want to plant a new item into your garden, you’ll scrape the mulch back and will then see (and remember) the dripline before digging the spade into it!

Our dripline is a brown tube approx. 17mm wide and comes in 25 metre, 50 metre or 100 metre rolls. Every 33cm along the inside of the tube is a discrete drip mechanism. This is visible from the outside of the tube by a small hole, about a millimetre or 2 wide. Each dripper allows exactly 2.2 litres of water out per hour. This means that a line of dripline will deliver the water very accurately. In a garden situation the best way to install the dripline is in lines about 40cm apart. This means that any given plant can find water from the dripline tube no more than 20cm to the left or the right of it, and then along each of those tubes every 33cm. A bigger plant will be able to drink water from multiple drip points along each dripline tube.
Please note that newly planted plants need to be hand-watered a few times until they grow their roots, and to allow some capillary action within the soil. Dripline is best with perennial and long-term gardens. It is also great in gardens where you might not want to get the foliage or flowers wet (such as roses) to minimise water damage and fungal diseases.

Garden Sprinklers:
We have a range of garden sprinklers that will spray the water above the plants. This system is great especially for annuals and herbaceous perennials, and for lush growth such as rainforests where good overhead coverage is beneficial.