Irrigation

The time to save water is now – Irrigation innovations and efficiencies

Paul Jeffery, Managing Director of Waterscapes Limited, discusses how efficient irrigation has to be in the forefront of everyone in the landscape industry

As landscape professionals and end users alike, we have to identify that the water we use is not a limitless resource, and where we can, we should make every attempt to reduce our consumption as an individual, an organisation and as a worldwide population. The use of water in the landscape is essential for growing and maintaining, and if we want to keep those planted environments bright, healthy and lush, we have to water more efficiently.

In recent years, many of the worldwide irrigation manufacturers have released new innovative products to help designers, installers and users achieve this possibility (of efficient watering). From intelligent sprinkler nozzle design to non-blockage, sub-surface driplines; and from cloud accessible controls to improvements in moisture sensing and interaction, the world of landscape irrigation has leapt forward. With greater changes in seasonal temperatures, changes in rainfall patterns and extended dry periods – all related to the climate challenges faced by the entire world, the importance of efficient watering can only get more and more important. When irrigation is essential, we should be clear on our efficient best practice: Water Source – The majority of UK irrigation systems are supplied from mains water or ground water (boreholes, lakes etc) but does the project have any other untapped sources? Rainwater from roofs or hard surfaces can be used if filtered and treated correctly but ‘it never rains when you need it!!’ so consideration needs to be paid to correct sizing of any collection vessel or tank for rainwater.

Control – The less manual watering the better, efficient watering is better achieved by automatic control. The majority of modern irrigation controllers have the ability to monitor water flow and detect leaks, interact with sensors and permit remote access by Wi-Fi, 4G or LAN so they can be checked and managed remotely.

Moisture Sensors – Technology in sensing the level of moisture within the soil has improved dramatically. Sensors will interact directly with the irrigation controller, adjusting cycle time to achieve the optimum water applications – only replacing the moisture lost through evapotranspiration and plant use, instead of blanket watering.

Image by Willerby Landscapes.

Spray and Drip Irrigation – Spray irrigation technology has also moved forward leaps and bounds with highly efficient nozzles from all manufacturers but ultimately the most efficient way to water any plant is directly to the roots. Sub-surface dripline (where appropriate) now represents the most efficient method of applying water but has its drawbacks. As a contractor it is susceptible to damage at installation stage and also post completion when the Client or landscaper needs to dig.

RainBird XFS Sub-Surface Dripline.

Ultimately, if an irrigation system has been designed correctly, using the ‘right product, for the right planting, in the right growing medium’ and is regularly maintained by skilled operators, the customer should have the confidence that providing they use their irrigation system as designed, they will be doing their part in helping to reduce unnecessary water usage, and protecting this precious resource.

‘Conkered’ by a miner

Celebrated by children who clamber around their roots for fallen conkers, the horse chestnut tree epitomises autumn. But it is not the young folk that this deciduous flowering plant needs to be wary of

A host of bugs usually appear in April to prey on trees and shrubs but the recent cold snap early in the year may have proved a stay of execution for some species.

“The dip in temperatures most likely pushed things back a little,” says Dr Jon Banks, Research Lab Manager at Bartlett Tree Experts, “but plenty of undesirable things will be coming out very soon.”

One of those “things’ being the horse chestnut leaf miner. These tiny moths emerge from leaf litter just as horse chestnuts burst into leaf, feeding off the fresh green foli-age to leave unsightly trails and brown, crinkly remains.

The trees can even drop their foliage mid-season, giving up the ghost for the year in the hope of a better climate next time round.

Leaf miner, and another blight affecting the same species – horse chestnut bleeding canker - spread alarm across the UK when they first struck some 15 years ago but things are improving, Dr Banks notes.

While leaf miner is endemic now, arborists, landscapers and grounds managers are finding ways to combat the condition, he says.

“The moths typically emerge just after the tree’s leaves have expanded. Disposing of leaf litter can help reduce or prevent outbreaks and while no licence is currently available specifically for treating horse chestnut leaf miner, spraying with a broad-spectrum systemic insecticide, such as synthetic pyrethroid (trade names include Decis and Bandu) designed for amenity trees, is proven to be effective,” he ex-plains.

“Tightly focusing the spray using a lance targets the treatment liquids where they are most needed,” he says. “Ideally, apply the liquid until just before run-off occurs as that ensures maximum adhesion to leaves.”

Turning his attention to larger specimens, Dr Banks adds that Bartlett Tree Experts have developed tailored management services, using spray equipment designed to safely deliver plant protection products efficiently and effectively to the canopy.

“Leaf miners have three generations during the summer so follow-up spraying is critical, he states. "Two treatments usually are applied. The first, in April or May, lasts three to four weeks, then it’s time for the second application. However, a third spray will provide better coverage for the full season.”

Lance spraying also delivers ecological benefits, Dr Banks believes. “We’re not just spraying for our own sakes. Losing leaves mid-season deprives wildlife of habitat and the less spray that falls where it is not needed or where it may cause harm, such as any nearby water, the better.”

Spring is a time when clients realise their trees are not in full health, or are dead and yell for advice, he says. “It’s a good time to look at trees as often we can see branch structure very well but also gain an idea of what’s coming into leaf, depend-ing on the species.”

The good news about horse chestnut bleeding canker, which is caused by the pseudomonas bacteria, is that more trees may be tolerating the disease due to system induced resistance, he adds – because wholesale loss of our conker trees would deprive new generations of children of a favourite pastime.

Just the job

With 6 Bar pressure ceiling, the Berthoud Cosmos 18 Pro is tailor-made for treating trees using its giant telescopic lances, extendable to 2.4m or 3.6m and made in light, robust, rigid composite materials.

Highly chemically resistant and mechanically tough they come with hose, quick con-nect adaptor and profiled handle.

Visit www.berthoud.fr/en/ for calibration formulae and nozzle-to-target distances.

Leaf miner up close