Sunday 17 January 2010

How I am trying to keep an olive tree going in freezing temperatures.







Common wisdom, as I have read it, indicates that an olive is ok down to -7deg C. I am sure that there are opinions either side of that figure, but in recent days when temperatures in our area of NE Lancs dropped to -18, I was worried for my tree.
We have an approx 80yr old olive tree, from Jaen in Spain. It has happily lived in a small corner of our courtyard for a few years and with virtually no care has got through recent winters. I have recently read Rosenbaum’s book on the Olive and the description of the decimation of trees due to severe cold was suddenly a looming concern. The garden was virtually built around the tree and replacing it would be a financial and emotional trauma.
I had put a set of LEDs in the canopy for Xmas..and decided to leave them in. They seem to generate virtually no heat.. but I thought that over a few hours they might just lift the temperature enough. Leaving the canopy open to the elements would allow any warmth to simply be blown away, and following what I have seen in urban gardens in Spain in winter, I wrapped the canopy in a fleece. I ran out of fleece, but a local Asda had an offer on pet bed fleeces (£1.99) and two were enough to double wrap the trunk (held on with cable ties). Next I mounded up bark chippings up the trunk as high as I could go and covered it in a “cone” of plastic sheeting. Mostly this was to keep the cat off who might dig it all off, but I figured it would also keep the snow off the bark and save any water getting into it and freezing. I tried this for a few days. The snow arrived and sat 6” deep on top of the fleece, I thought this might actually add insulation and with the lights turned on it made the tree look like some spectacular mushroom sculpture. But the temperatures promised to dip further, so an additional technique was employed; tea lights around the base. Vineyards use heaters to dispel frost , so could I. They seemed to last about 2 ½ hours, and I used three at a time. Which required a few late nights to ensure there was a fresh set burning around 1am, and that the accumulated heat was enough to get through to morning. The heat I had hoped was retained in the canopy, just enough to keep the worst of the cold off. O one occasion a candle slipped and started to burn the sheet over the bark, throwing snow at a flame seemed like a good idea at the time, but I will stand further back next time! If you look carefully at the picture, there is a tin can hanging off a branch. I added another tea-light here to give a boost.
Was a tree ever as cared for? Despite all this effort, and the fleeces are staying on until spring, I wont know until spring if the effort worked.

No comments:

Post a Comment