Drip irrigation is an incredibly versatile approach to watering for both residential and commercial spaces, and can be used in far more scenarios than first meets the eye.
If you’re keen to save both time and money on the upkeep of your garden, there’s a good chance drip irrigation can help you achieve that goal.
Drip irrigation can be as simple as a soaker hose or two controlled via your existing garden tape, or as complex as a highly automated zoned irrigation system with pump, pressure regulator, filter and rain sensor for a truly responsive approach to watering. Whatever your budget and level of expertise, drip irrigation can be set up with your individual circumstances in mind.
From the length and layout of piping to sprinklers, drippers and soaker hoses, careful planning can ensure your irrigation system is both appropriate and water-wise.
For anyone new to the world of irrigation, the number of options can be a little intimidating. To help narrow down which methods and components are most suitable, keep reading to learn the ins and outs of drip irrigation
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What Are The Benefits Of Drip Irrigation?
By releasing water drip by drip – hence the name – drip irrigation (or micro-irrigation) delivers water directly to the soil at the same rate at which it’s absorbed, making it far more efficient than a hose or watering can. Watering manually can be one of the most tedious tasks when it comes to garden maintenance, so the ease and convenience alone is a huge factor in the popularity of drip irrigation.
Widely considered to be one of the biggest advances in modern agriculture, the benefits of drip irrigation aren’t limited to commercial or large-scale farming operations – drip irrigation is versatile enough that gardeners around the world utilise drip irrigation in their own backyards or to maintain commercial landscaping.
There are a number of benefits to installing a drip irrigation system:
- Vastly improves water efficiency and minimises water bill – surface watering means significant water waste via run-off and evaporation, particularly when using overhead sprinklers, while drip irrigation can reduce water usage by more than half
- Avoid both overwatering and underwatering – when watering manually with a hose, it’s virtually impossible to know how much water you’re applying and to which regions, while drip irrigation cuts through the confusion with reliable flow rates and volumes
- Encourages a consistent watering schedule – the hands-off nature of drip irrigation makes it easy to keep up regular watering exactly as your garden requires it (every 1 to 3 days is ideal) and can be run on a timer during the cooler hours
- Watering style encourages healthy root development – the optimum approach for strong root growth is to water thoroughly and gradually, over a period of hours, rather than in short bursts more frequently
- Helps prevent fungal diseases and weed growth – delivering water right to the roots keeps moisture away from the leaves and avoids inadvertently watering the space between plants, depriving weed seeds of the moisture they need to sprout
- Conveniently deliver fertilisers and treatments – this ‘fertigation’ approach simplifies the process of fertilising and is more effective in reaching plant roots, leading to healthier plants and cost savings over time
- Helps soil retain key nutrients – when watering traditionally, free water run-off can easily leach vital nutrients from the soil and carry them away from the roots, undoing the hard work you’ve invested in boosting soil quality
- Allow for use of recycled or non-potable water – in most areas, recycled water cannot be used via overhead sprayers or sprinklers due to the high level of evaporation, so drip irrigation opens up additional water sources while minimising contaminant issues
However, there are also some limitations and pitfalls that can make drip irrigation a less appealing option:
- Initial costs to purchase and set up – while drip irrigation is often considered a worthwhile investment, different factors such as size and slope of the land to be irrigated can require more complex components such as pumps and pressure regulators
- Complexity and range of options – with the number of components and emitters commercially available, as well as calculations and layout planning required, the learning curve can be quite steep for beginners if a simple soaker line or starter kit isn’t suitable
- Can be prone to damage and clogging – the small size of drip irrigation emitters means that dirt particles can block water flow, requiring regular oversight and maintenance in case any issues are detected, though installing a line filter and regular flushing can reduce the risk
it can be well worth enlisting the help of an experienced irrigation and landscaping specialist to recommend the best set-up for your space, ensuring you’re making the best investment possible in the long term health of your garden.
How To Choose The Right Type Of Irrigation?
There are a few factors to consider when deciding what kind of irrigation is best suited to your space:
- Plant varieties: Different types of plants not only vary in how much water they need and how often – they also have preferred methods of water delivery, from root drippers to sprayers and sprinklers.
- Garden layout: The shape and size of your lawn and garden beds will determine what types of irrigation are suitable and how many outlets are required to cover the space at the designated flow rate. Extensive areas or sloped terrain will require a pump or pressure regulator to ensure the water reaches throughout the system.
- Soil type: Depending on the type of soil in your yard or garden bed, water will accumulate or drain at varying rates. Sandy soil both absorbs moisture most rapidly, while clay soil will require a lower flow rate to avoid flooding the surface.
- Water restrictions: If water restrictions are in place or anticipated, this can be factored into the design of your irrigation system, enabling you to meet water usage requirements and water at accepted times of day without compromising on the health of your garden.
What Types Of Drip Irrigation Are There And How Do They Differ?
The three main goals in designing a drip irrigation system is to ensure:
- The area you want to water is covered completely, without any gaps
- Sufficient water is being delivered to that area and penetrating the soil effectively
- The rate and method of watering is suitable for the plant variety
Piping can be laid underground (sub-surface irrigation) or above ground (surface irrigation) depending on your preferences and requirements. Sub-surface piping is more protected from the elements, which extends the lifetime of your components, but is naturally more expensive and disruptive to install, so is less common in domestic yards.
While you will need to select enough piping to reach all areas to be irrigated and ensure pressure is sufficient through main and sublines – including a pump or pressure regulator if the area is large or hilly – the key decision for plant health is which emitters to attach to your irrigation piping.
When choosing your emitters, the biggest considerations are the flow rate and area covered as well as the method of delivery – such as a slow seeping soaker hose, dripper, sprinkler or bubbler. Even within these categories, emitters come in a range of flow rates from 1 to 10L per hour, so you can select the correct option for each plant variety.
Some common emitter types are:
- Dripper: Delivers a steady, slow supply of water directly to the roots of an individual plant for maximum absorption. Drippers vary in flow rate to suit different plant varieties and sizes, and can be used in container gardens.
- Drip line or soaker: Ideal for hedges or row-planted vegetable gardens, many drippers are set into a line of pipe which waters evenly throughout the garden bed. You can opt for custom spacing or use a pre-prepared drip tape or soaker hose.
- Bubbler: Similar to a dripper, but allows for a greater flow rate, suitable for larger plants and trees.
- Garden sprinkler/sprayer: Smaller than typical lawn sprinklers, these offer a rapid flow of water for densely planted garden beds. Sprayers are fixed in place, while sprinklers rotate to cover a wider area.
- Pop-up sprinklers: Perfect for keeping your lawns lush and green, pop-up sprinklers use sub-surface piping and slot conveniently out of sight when not in use.
When Should Drip Irrigation Be Used?
The magic of drip irrigation is its flexibility, and a drip irrigation system can be fully customised for the size and terrain of your green space, including the soil type and the plant varieties currently established.
From small backyards to vegetable gardens and even landscaped commercial grounds, no garden is too small to benefit from a well-planned drip irrigation set-up.
The low-flow nature of drip irrigation does make it less suited to larger regions of low-value vegetation, such as lawns and fields. In these scenarios, particularly when water conservation is less of a concern, overhead sprinklers or flood irrigation can be more practical and will get the job done.
But when the goal is to maximise the health and wellbeing of plants – both edible and ornamental varieties – drip irrigation is an excellent investment.
How Long Should I Run My Drip Irrigation System?
The length of time you’ll need to run your drip irrigation system – and how frequently to use it – will vary depending on the pressure and flow rate of your set-up and the kind of soil present, as this affects the absorption rate and penetration. Emitters such as drippers, sprayers and sprinklers will each have their own flow rate per hour at a given water pressure.
If you’re uncertain about the flow rate or how it will perform in your individual scenario, it’s a good idea to run some experiments to tell you exactly how your irrigation system is functioning. This will allow you to adjust the running time and water pressure as required, or even switch to an alternative emitter if the results aren’t what you’re looking for.
The simplest way to measure flow rate in practice is to collect water from a single emitter for a length of time, then calculate what that measurement would be for per hour of running time.
To test absorption and watering depth in the soil itself, there are a few different methods you can use – the simplest being to dig to the desired depth (around 20cm) after watering to check the condition of the soil. If that’s a little too hands-on, particularly when it means digging up your neatly-planted garden bed, a soil moisture meter is a helpful and inexpensive piece of equipment that makes this process a lot more reliable.
Investing in a soil moisture meter – which start at under $20 – is a enormous help when setting up and configuring your drip irrigation system, as well as evaluating and adjusting your approach from season to season.
If you’re using a soaker hose or drip line without a pressure modulator, you’ll also need to consider the water pressure – in this case, entirely dependent on flow through the tap. Turning the tap on partway is typically the best approach to keep the water seepage slow and steady without flooding the soil, but this can be evaluated and experimented with in along with the running time until you find the perfect combination.
Once you’ve identified the best running time for your needs, you can make things even more convenient by setting up a timer. These can be mechanical or digital, so price points vary depending on how ‘smart’ you’d like your irrigation set-up to be.
The most important thing to remember is that it’s best to water more thoroughly, less frequently – every 1 to 3 days is ideal, watering more frequently for young plants and in warmer weather, and less frequently for established plants.
When it comes to drip irrigation, increasing the running time also increases soil penetration. If you’re having trouble saturating to the right depth, the solution may be to run your irrigation system for longer at a lower flow rate, rather than simply bumping up the quantity.
Should I Use Drip Irrigation For Large Or Small Areas?
Drip irrigation encompasses a few different methods of irrigation and various emitter types, so it can be suitable for many different spaces. To effectively irrigate large areas with diverse plant life and landscaping styles, it’s a good idea to divide the area into irrigation zones, each with specific watering needs depending on plant varieties, soil types and terrain.
Small areas can also be suited to drip irrigation – small and uniform garden beds can benefit from soaker hoses or sprinklers which are very cost-effective and require minimal set-up. Even container gardens can be suited to drip irrigation, utilising the right connectors and drippers to allow water flow at the required angle.
Is Drip Irrigation Expensive To Run?
While setting up a drip irrigation system does require some initial outlay on equipment and installation, that investment pays off generously in terms of both time and money saved in the long term. By delivering water right to the roots in a slow, targeted manner, drip irrigation significantly reduces the amount of water needed and prevents nutrient run-off.
By avoiding the accumulation of moisture on leaves and stems, drip irrigation also helps prevent fungal diseases and pest infestations, which can be costly to treat. And by delivering water right where it’s absorbed by established plants, an effective irrigation set-up also discourages weed growth in your garden beds, ultimately saving you time and money by reducing upkeep.
Sam Christie is the owner and operator of Christies landscapes, founded in 2013 Sam and his team of landscapers and designers have many years experience in the landscape construction industry. Over the years they have developed and refined a broad range of skills, qualifications and techniques to deliver outstanding projects throughout the Canberra region.