Nearly two years ago I wrote in this column about street trees and I was extolling their virtues. I also listed a few that would be and in some cases are, very useful and long lived shady street trees. Maybe they should be planted widely as street trees before our streets are reduced to barren rows of memories of trees.
The trees I suggested then still stand (excuse the pun!). The criteria I’ve used includes such attributes as the ability to survive only on natural rainfall in the Riverland and Mallee once established; will happily grow on a range of soils; must be frost tolerant; not overly ‘messy’, particularly with regard to asthmatics; must have a sufficiently dense crown to provide useful shade; and must not have an overly aggressive root system to cause problems with drains and pipes. To follow is part of my list of favourites and I’m sure many of you will have their own favourites, but will your choices stack up against the odds?
The weeping myall, Acacia pendula, is a graceful weeping grey green wattle that will be quite erect in growth, gradually spreading as they age. They have inconspicuous flowers in spring. There are good examples on Bookpurnong Terrace, South of the Roundabout in Loxton.
Broughton willow wattle, A. salicina, is an exceptional tree from the point of view that it will survive almost anything, and be fresh, green and cool looking. It is another weeping tree and has pale wattle flowers in spring. There is a good example just west of the Berri Post Office. Just look for the tree with four or five cars parked under it on most week days.
Brachychiton populneus kurrajong is a multipurpose tree, in that the seeds can be eaten once roasted and is valuable stock fodder. Its fresh green leaves can make the hottest street appear cool and inviting. It has cream bell flowers followed by boat shaped pods. Wilson Street in Berri used to be full of them, however many were cut down in 1998 because they ‘dropped leaves’. Fortunately some on the West end of Wilson Street still remain and can give an idea what a wonderful shady street this used to be. Here we are, fourteen years later, and the shade has still not been replaced.
Casuarina pauper, black oak, can be slow growing to start with, but becomes a very permanent tree with highly valuable timber, has leaves that are actually modified stems (the true leaves are reduced to minute ‘teeth’). The fine foliage makes the most restful sound with any sort of breeze. An old original can be seen between Berri and Glossop on a bend at the junction of Old Sturt Highway and Hardwick Road.
Eucalyptus brockwayii, Dundas mahogany, is a western Australian upright tree with a clean bronze trunk and shinning leaves. A good example can be seen in the medium strip just over the Paringa Bridge, on the Paringa side.
E. leucoxylon megalocarpa, large fruited SA blue gum, is a particularly densely crowned tree with masses of red flowers in autumn and winter. It usually has a clean white trunk. A good example can be seen on Tanko Street, Loxton. You will know it when you see it as it has such a dense crown, which is unmistakable.
Geijera parviflora, wilga, is quite a common tree to the north and east of the Riverland and Mallee but is almost unknown here. It is widely planted as a street tree in California and is called the Australian Willow. I was delighted to see it used as a street tree in Wilmington, SA. Its fine drooping leaves and cool appearance would make a street well worth living in. A good example can be seen in a property on the South West corner of the junction of Old Sturt Highway and Jellett Road in Berri.
Santalum acuminatum, quandong, could also be used a fruiting street tree. It has a weeping habit and is quite a sturdy little tree. It has almost become a plant of mystery as it can be difficult to establish but very hardy once it is. The tree itself is beautiful; particularly with fruit which are quite clean and dry. I can imagine the wonder of a street in full, bright, red, ripe fruit.
We, as a community, have no excuse not to have leafy, green, inviting and cool streets. With our climate of more sunshine than the sunshine coast, we probably have greater need for a high degree of street amenity. So you now have part of my list, add to it and start planting. As the Chinese say, the best time to plant a tree was fifty years ago, the second best time is now!
This article first published in the Riverland Weekly © April 12, 2012.