Wednesday, April 15, 2015

The expat Chestnut

The story of the American Chestnut is a real-life ecological morality play, that I have been familiar with ever since I was young enough to recognize the red moldering logs for what they were.  Whole books have been written about the destruction of Chestnut forests, and internet summaries abound. Since then, I have moved to Australia, settled down, and, in due course, bought a house and started playing with the yard. Australia is renown for its biosecurity, and there is no endemic chestnut blight here.  A few years ago, I started a search to see if I could find some American Chestnut trees, to see if they would grow here. 

Canberra is not the ideal climate for chestnut trees.  The annual rainfall here is about half what it is in the eastern US, and there are soil fungi in some areas which will kill their roots.  Never-the-less, after a few years of false leads, last autumn, I managed to get my hands on a few seedlings.  I planted three in my yard.  The first, planted in the chook pen, leafed out in spring, but never really grew much, and during the February-March dry spell, it turned brown and shriveled up.

The second tree is in the western corner of the yard, where it is exposed to both the hot westerly winds and the cold southerlies.  While it didn't grow much, It did hang onto its leaves until the first cold night, and it is now changing color.  I don't know how it will cope with the native acacias around it, and whether their shade will help reduce evaporation or their competition for moisture will hinder, but it seems to have made it through the first year.

The third tree is in a more sheltered position, where it gets morning sun but is sheded for the rest of the day by the neighbour's hedge.  It has only just begun to change leaf colors, and put on a decent growth this year.  By North American standards, the Canberra winters are not particularly harsh, so hopefully these trees will enter dormancy, sleep well through the winter, and continue to grow.
The half-dozen or so North American trees commonly planted here have a mixed history.  The tulip trees tend to suffer and die off at their tops during drought years, and the sweet gums and pin oaks also suffer during long dry hot spells.  But there are quite a few upland oaks which are doing OK. Only time will tell how Castanea dentata fares in this strange new world.

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