A basic guide to Drip Irrigation

A basic guide to Drip Irrigation

Proper irrigation is an essential aspect of healthy garden maintenance, because it only applies water where it is needed in controlled amounts drip irrigation is great for conserving water and there is no special technical equipment required for a standard garden drip irrigation system.

You can reduce your water bill substantially with a drip irrigation system (sometimes referred to as trickle irrigation). A drip system aids in maintaining the health of plants and irrigating the soil through a system of tubes and water drips. By only irrigating the space where the plant’s root is situated, evaporation and water loss is reduced. A drip irrigation system also helps to control fungal and weed issues as other watering methods can be prone to creating spots of lingering water.

Of course, you might want to get an expert gardener to do all this for you, on the same page we also have information on other types of garden irrigation systems such as sprinklers, otherwise read on to get started with drip irrigation.

Map your garden

The first step requires garden mapping to establish how the irrigation system is will be positioned and what plants it will be used on. It's important to work out the amount of water the different areas of your garden will need. For optimal results, you should have individual pipes for every kind of plant that you have, since each plant group warrants a different watering amount. In fact, natives, vegetables, and fruit trees all require specific quantities of water so you may want to have different irrigation zones.

Drip tubing

‘Backbone tubing’ starts at a water source and is run as needed to supply water for the rest of your system. The thicker this main pipe, the higher the initial flow rate, where dripping holes are situated will also affect how much water will be emitted for each square meter. ‘Micro tubing’ is the term for the tubes that you insert the emitters into, tubing can be purchased in either vinyl or poly rolls. Vinyl tubing is softer than poly and is easier to work with. Poly tubing is harder to work with initially, but it withstands UV rays very well and does not expand when heated.

Drip tubing that is pre-punched with holes for the emitters can be acquired from your local garden centre. You can also buy non-perforated tubing, but you’ll need to make the required holes and insert the emitters yourself. Purchasing non-perforated tubing is best for irregular garden designs so that you can modify it based on the needs of your garden.

‘Dripline’ is tubing that has the emitters already embedded directly into the tubing, it will have designated spacings and dripper ratings, the can save you a lot of time if your garden is of a very formal garden design.

You should keep the water point access and tubing length in mind. To have enough water pressure the length of the tube shouldn’t exceed 60 meters from the water’s entry point to the end of the tube. As such a tube can be as long as 120 meters if the water’s entry point is in the middle. There are various tube sizes for specific plant types. For the most part, drip tubes range between 12 mm to 20 mm in diameter.

You will need to use an end cap or water will flow out to the opposite end and flood that part of your garden.

Flow and emitters

Emitters are the devices that you insert into your drip tubing, the emitters must correspond with the tubing they are constructed for. If the tubing isn’t the right fit, the emitters will come off the fitting, or the installation will prove to be troublesome.
Emitters regulate water flow. There are several kinds of emitters with capacities that range from 2 litres/hour to 8 litres/hour. Most of the emitters are categorized based on how they regulate water, as well as the way they’re designed. The proper emitter type is required to control water flow. You need to keep in mind the kind of plant being irrigated and how much water it will need each day.

“Mixing different emitter flow rates together on the same system is not a good idea. Pick a single flow rate and stick to it. Plants that need more water should have more emitters per plant”

Here is a good article on how to select the best drip emitter for what you need.

Of course, that is an American site and the brands of emitters available will be different in Australia, but it will definitely give you a good idea. Once you know the emitter flow rate that you are getting from your chosen emitters you can use the following calculator to help you decide how many emitters you should use per plant:

http://irrigation.wsu.edu/Content/Calculators/Residential/Drip-Design-For-Landscapes.php

Make sure you use this for each different type of plant and enter your correct local climate type.

Also note that there are advantages and disadvantages of burying emitters underground, but generally it is discouraged for a simple home installation, however if you wish there are distinct emitters you can buy for underground emitter placement.

Flushing your drip system

Sediments settle over time because water flows slowly through a drip tube. Sediments will progressively accumulate and will need flushing out occasionally. This should be performed annually. Algae might also build up over time in tropical regions and then you will need to flush more than often than once a year.

Drip system considerations

For both connecting your water system to the hosepipe and to connect your hosepipe to the tubing you may need a tubing adapter, have a look at the ends of the tubing when you are in the garden store and ask someone if you are unsure. It is best to use a separate hosepipe that you can buy at the same time as the tubing, keep your old hosepipe for other things.

It is essential to always use a backflow preventer if the source of your water is a clean water system. They stop water from traveling back in the wrong direction. This prevents the clean water from being contaminated by salmonella, dirt, and various other types of bacteria.

Most drip systems are run at a reduced pressure in comparison to other water pipes. Water force can be slowed down with a pressure regulator, which is probably going to be necessary if water pressure is greater than 2.8 bars.

Emitters have very small holes, which can easily clog up. Water filtration is paramount or you may end up needing to replace the tubing regularly so a water filter should be used. This is true even if clean water is being used from your home because water coming from the house is not always totally pure; grains of sand and rust sometimes linger within the pipes. The filter will remove these fine particles from the water.


Mark

Part of the expertEasy team in Melbourne. Mark is a keen gardener and is quite knowledgeable on the subject. He is originally from Perth and is a true Eagles fan.

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