Let it soak in: irrigation is necessary in Irish gardens

Charlie O’Leary, landscape designer at the Pavilion Garden Centre, says we underestimate watering needs.

ONE of the most common Irish landscape misconceptions is the quantity of watering required in our very unpredictable and changeable climate. In Ireland, we associate irrigation with golf courses, or with sunnier resorts on the Continent. But for long periods during our spring and summer, rainfall levels are not adequate to keep our gardens looking lush and growing strongly.

We are all keenly aware of the water charges and how they will impact upon our gardening budgets over the next few years. While we can’t promote or condone leaving the hose running indefinitely in the back garden, with some investment you could provide a very economical and sustainable watering solution for your property.

Rain barrels, or water-attenuation tanks, are definitely an important consideration for any gardener who wants to irrigate without the water-mains charge. Rain barrels can be connected directly to the house down-pipes, and can be fitted with a pumped hose to aid the traditional hose-and-spraying watering technique.

In larger gardens and in new-builds, it would be worth considering a subterranean, rain-water harvesting tank. These large units are buried out of sight and have a much higher capacity than a traditional rain barrel.

This kind of water harvesting is not just for the garden — it can be incorporated into your plumbing system and provide water for flushing toilets.

If you have a larger property, there might not be much time for watering the plants during the day. In this case, you should consider a drip-irrigation system. Once a water source is established, such as those mentioned above, a header pipe is run around the garden beds, and is fitted with PC Junior valves — these ensure that water is distributed evenly along the watering line only when water pressure reaches 1bar. This pump system can be managed by digital control to ensure that plants are watered for the right amount of time, and at the correct time of the day.

Benefits of drip irrigation systems

No wasted water — water quantity can be managed depending on the season and based on predicted monthly rainfall figures. Automated systems can be installed and these are based on rainfall levels and soil humidity.

Regular timing — Plants are best watered well before the sun is high in the sky; before the sun starts to evaporate the moisture. In a similar fashion, if you have to use the spray hose, make sure to carry out this kind of watering early in the day. It’s important that the leaves are dry before the sun gets to a height in the sky; otherwise, scorching can occur as the water is burned-off the leaves.

Disease prevention — If you have to use the spray hose, do so early in the day, as it is important for maintenance of plants, particularly roses, which suffer from fungal diseases. Early watering allows enough time for water to evaporate from leaves and wood, so that when temperatures drop at night there is less threat of fungal disease development.

Sprinkler systems are best utilised for lawns — drip irrigation systems get water directly to the plant roots, whereas sprayed water can gather on plant canopies and may not get to the base of the plant, where it is required.

For further information on garden concepts and design, you can contact The Pavilion Garden Centre by visiting www.thepavilion.ie