Street Trees: In the urban environment there is nothing that gives an area a feeling of peace and tranquillity than a street lined with trees. Unfortunately there are many streets that have been planted (with the best of intentions) with totally inappropriate trees. Usually these trees are too tall, too spreading and, in some cases, too prickly for street planting.
The main fault is that tree species are selected that are too tall and grow into overhead power lines. This presents a fire hazard; also broken branches may bring down power lines causing a risk of electrocution.
These trees require constant lopping to keep them below the power lines. This usually ruins the shape of the tree but more importantly is a constant drain on the resources of the electricity authorities who have the responsibility of managing the vegetation. Also the personnel involved in tree lopping risk danger to life and limb.
In Armidale, northern New South Wales, a row of Claret Ashes were planted, many years ago, under high voltage power lines. The Claret Ashes have to be lopped every two years. These trees are shadows of how they should look.
In many areas of Sydney, Brush Boxes (Lophostemon confertus) have been planted as street trees under power lines. These giants of the forest are totally unsuitable for this purpose and have to be regularly mutilated to keep them clear of the power lines. The photograph on the left shows a mutilated Brush Box in a street in Westmead, a western suburb of Sydney. Brush Boxes have been used inappropriately in many western Sydney suburbs. Keeping these trees lopped in a constant drain on electricity authority resources. We have observed street after street with Brush Boxes planted under power lines.
Some trees grown along streets have spreading canopies that cause problems. The branches intrude on footpaths and roadways. They also have to be lopped on a regular basis.
Trees with prickly foliage are not as big a problem as the previous examples because they not usually grown as street trees. One exception, that we have observed, is a street in Uralla, in northern New South Wales. Cedrus deodara trees have been planted along a street. Apart from their height and spread this species has very prickly foliage that is a danger to pedestrians.
Whilst composing this tirade we visited Sydney and observed another inappropriate tree planting. Three Eucalypts have been planted on a footpath in Westmead (see right image). There are no power lines but the trees have been planted near a set of traffic lights. In the fullness of time these trees will block motoristís view of the traffic lights and a speed advisory sign. The spreading branches will also intrude onto both the footpath and roadway creating more hazards. It is likely that, in the future, these trees will have to be removed.
One a more positive note we should mention some native plants that could be used for street landscaping without causing any of the problems mentioned above. Banksia marginata, Callistemon Candy Pink, Callistemon Endeavour, Callistemon Pink Champagne, Hakea laurina and Hakea salicifolia. A number of Western Australian Mallee Eucalypts have been used successfully for street landscaping. Eucalyptus macrandra and Eucalyptus erythrocorys are two examples.