Oak trees

[Nicola Christine]

We have several very old oak trees, both in the garden and on the farm (three are probably over 250 years old). Normally they would have shed all their leaves by now, but this year even after 18 inches of snow, they still retain about half their leaves. Has the cold affected the leaves in some way, preventing them from falling? Even when it has been quite windy, none are coming down. I would like to hear if anyone has noticed the same phenomenon, and what the cause might be.

[Dorts]

I have noticed a number of large Oaks in this area are similarly holding onto many more leaves than normal this winter.
Beech and Oak, more than any other broad-leaved tree, do this, especialy when young or when clipped into a hedge. Though it is far less common on large old trees.
It is apparently something to do with the gradual release of the nutrients in the old leaves to the soil. Though why this should only happen occasionaly in large trees has yet to be determined.
Dorts.

[treewee]

The abscission of leaves on oaks does seem to vary in date from year to year. It never seems to be determined by the temp. Possibly less aphid or gall wasp infestation this year?