How can Irrigation save water?
21/02/2020
Irrigation has come a long way in the last couple of decades. Back in the day, big gear-driven pop-up sprinklers (like the ones you see on golf courses) were used to water not only lawns, but even borders and beds. As a result, many systems were inefficient and unreliable.
Fortunately things have moved on and modern irrigation components are robust, efficient and long-lasting and there’s so much more choice. So, whatever your circumstances, there’s a product to suit your garden’s needs.
You’ll know that some customers just want a green garden, end of story. They measure a successful garden by how green it is, and nothing less than the greenest green will do. For those customers who want ‘the full monty’, you can give them what they want; a large tank & pump system fed from a borehole or with harvested rainwater, supplemented with a mains water top-up using zones of pop-up sprinklers for the lawns and micro-sprinklers or dripline for the borders and beds.
We know that some people are uncomfortable, from an environmental point of view, with the idea of blanket irrigation coverage in a garden. Another interesting perspective is that some fundamentally think irrigation is wrong and that one should only select plants that can survive in that particular environment. Now there is some validity to this point, in an academic sense, but in reality, this approach often doesn’t work in the vast majority of gardens being built.
Because, conditions vary so greatly and in some gardens you simply wouldn’t be able to grow anything without the aid of an irrigation system. Customers don’t have time to fit hand watering into their busy lives.
Garden Designers and Landscape Contractors like a broad palate of plants to choose from, but even carefully selected plants will require water in order to establish them.
Contractors and Garden Designers can only plant from the selection that is provided by the nurseries.
Customers want some ‘bang for their buck’... they want an instant impact when their garden is built and are not prepared to wait for small plants to establish and develop.
The reality is that the gardens we build are by their very nature contrived, we create a product when it should be a process and in order to give our customers’ value for money, we plant for impact and instant effect. None of this is wrong, it is just different and it shouldn’t be confused with the classical tradition where a garden evolves and is developed over a number of decades.
If a customer doesn’t want a full system, the garden is too big or the budget is stretched then we need to think about irrigation in a different way, we need to consider what we are trying to achieve and how we might go about achieving it. As garden professionals, there are several key reasons why we should use some form of irrigation in a new garden, for example, to establish plants, to minimise plant losses, to secure a customer’s investment in expensive plants and on occasions, and to meet the water requirements of nurseries in guaranteeing large shrubs and trees. Most importantly though you need to ensure your customers get value for money and your plants get the water they need.
So taking into account the budget and your customer’s wishes, the first step is to grade the plants in terms of their aesthetic value but also their monetary value, focus on the plants that you simply must establish i.e. the expensive ones like trees, large shrubs and hedges so that you can prioritise where you need to water. We know these plants won’t necessarily need irrigation indefinitely but they will need water in the first couple of seasons in order to ensure they establish and that is the goal.
Once you have identified your ‘key planting’ on a drawing, you’ll be able to visualise how they can be grouped together and seen, (in a larger garden context) as a series of ‘mini-gardens’. In a small garden you might only have one or two ‘mini-gardens’ but in a larger garden, you may have five, ten or more, it really doesn’t matter. Once identified, each ‘mini-garden’ can be treated as a local, independent garden containing a simple irrigation system. By taking this approach, you don’t need to install the infrastructure of a comprehensive system and the whole process becomes much simpler to organise, cheaper to install and can even be fitted retrospectively (although never ideal!)
For the 'mini-garden' approach, your first step should be to plumb the garden and get the water to each of your ‘mini-gardens’ ie run MDPE pipe around the garden and install a standpipe for each ‘mini-garden’. While you’re at it, install extra standpipes to make your customer’s life simpler so why not put one in the vegetable garden, another near the glasshouse and perhaps one more near the main lawns so that if the customer wants to use a hose and lawn sprinkler then they can do so without having to drag heavy hoses around the garden.
Once you’ve plumbed the garden, you’ll have created a water supply for each of your ‘mini-gardens’ and now you need to decide which method of applying the water is best for your customer’s garden and the plants you’ve selected (taking into account the aspect, location and local conditions).
A mixture of Micro-sprinklers, Mini-sprinklers and Adjustable Drippers that can be used to accurately water pots, containers and window boxes but also to water key plants. The benefits are that Micro-irrigation is very adaptable and quick to install. Additionally, you can adjust the application rates to ensure plants get just what they need which is especially important if you need to know exactly how many litres per day/week are being applied.
Not to be confused with Leakypipe or Soakerhose, In-line drip, when used as a network pegged to the soil surface, is a very reliable and efficient method for accurately applying water. To be effective, finish with a generous covering of mulch to minimise evaporation, encourage lateral movement of the water and to improve the aesthetics.
A new method of applying water via the use of MP (Matched Precipitation) rotator sprinklers that apply water evenly over the whole area (just like rain) providing a low-tech but cost effective method of watering. The sprinklers can be mounted on short stakes or fixed to the boundary fence/wall and then be removed when no longer required.
Use one or more irrigation control packs for each ‘mini-garden’ to switch the watering on and off and importantly, to filter the water. To maintain water pressure and flow, ensure the ‘mini-gardens’ are watered sequentially and overnight when evaporation is lowest and the water has the best chance to soak through to the roots of the plants.
Don’t forget that any irrigation should be used in conjunction with good horticultural husbandry to conserve water, so mulch well, mulch often and keep your garden weed free.
Are you looking to organise a day out for your staff? Looking to learn some new skills? Get advice on a build or want to give your students a more hands on experience? We can help!
From organising educational days to training in Ponds, Irrigation or Lighting we are always looking for opportunities to help build knowledge within the industry.
For more information on training days, to organise one of your own or arrange for us to visit you, feel free to call us on 01666 577577 or send an email to help@landscapeplus.com.
