17/01/2017

Street Trees

case-street_tree_case1There is a way not only to cope with less water when managing green assets, but to even improve on the results…

Way out west there’s a Scotsman from Dundee with 27 years’ experience in looking after public open space – John Christie, Manager Parks, Leisure & Environment for the City of Belmont, Western Australia. About the time he took up the role, three and a half years ago, the city’s street trees were planted under contract – 1,000 each year. What is remarkable, and for the wrong reason, was the failure rate which John estimates was somewhere between 75 and 80 per cent.

“It was basically due to poor planting practices and insufficient water, so we brought the planting back in-house. We increased the size of the trees from 45 to 100 litre stock – three to four times larger – and then reduced the number we plant to 250. We also adopted better planting practices.” From that point on there may have been fewer trees going in, but given their maturity, they had an increased impact on the landscape. And with the revised planting and management protocols, the survival rate now sits comfortably between 85 and 90 percent.

Part of this success is due to TerraCottem, which comes into this story around two years ago. “Being in this job, there are always people out there wanting to sell me almost anything – wetting agents to barbeque cleaning services. I think the reason I stopped to take a closer look at TerraCottem was because the people were genuine. On top of that they were willing to come over and educate the staff at no cost. We’ve some very switched on parks supervisors who took a close look at the technical information and they were keen to test it out.”

Applied to TerraCottem’s specifications as part of a landscape around the Civic Centre, the results soon showed that it wasn’t, as John puts it, “just another product”. TerraCottem The plants matured at twice the rate with virtually no losses and with a success rate of 98 per cent, which was quite remarkable given the planted areas are irrigated from scheme water and subject to water restrictions.

The logical step was then to write it, with expert advice from TerraCottem, into the street tree management plan. Each new tree goes into a hole ten times the volume of the root ball with a specific amount of TerraCottem mixed evenly into the backfill. (“We appreciate the value of the advice – one poor fellow was throwing it in by the handful, and the shrubs were being pushed out of the ground.”)

Not only has TerraCottem managed to take the sting out of once hostile sites like the asphalt-ringed round-about, but it has the capacity to reduce water consumption. “Currently our street trees are irrigated with part of our annual allocation on 7,500 kilolitres. That could well change, so we’re currently trying to determine the minimum needed to establish and maintain these trees – can we get away with irrigating them only once a week?”

As John points out, “If you’ve seen the results you’d know that this stuff is not the same as everything else.  And the advantages clearly outweigh the increased cost in applying it because you don’t have to get a crew back to replant new stock. I can’t speak highly enough about it – without question it’s done everything they’ve said it would do.”

To read more about TerraCottem soil conditioner and street tree planting, click here.