By Nickunstead
United Kingdom 
I have an English oak tree in my garden which is loosing its leaves later each year. 20 years ago, the leaves would be off the tree by late October. As the years have passed, the leaves stay on longer and in Dec 09 were still on well into the month. In Dec '10 , the leaves were still on the tree and mostly green despite the severe weather and are still on the tree now , Jan 8th 2011. Any ideas?
8 Jan, 2011
Answers
I bet it's ordinary (not meaning to be derogatory) quercus robur, English oak. I've got a photo (I'll post it in a few minutes) of oak still looking like summer, but the pic was taken during the snow recently. Perhaps the times are changing slightly, and our perception of events, too. There was no real wind and rain to knock the leaves off this last autumn, so they hung on. There was a question on here a day or so ago about a liquidambar still with leaves on it. Just the vagaries of nature. Worthy
8 Jan, 2011
I'm not sure how the UK's weather compares, but here in Arizona the fall and winter were quite mild right up until this most recent cold snap. Trees that are normally golden the second week of December waited until January this year.
8 Jan, 2011
Many thanks to all who responded, useful information all round
Nick
10 Jan, 2011
it may be that you have Quercus canariensis - this variety is semi evergreen, and its leaves persist in most winters, as with some other varieties of oak (Holm Oak and Q. phellos, etc.)
8 Jan, 2011