Hawthorn not shed its leaves
I have a little 'wildlife hedge' which consists of 2x hawthorns and a blackthorn that I planted this time last year. One of the hawthorns and the blackthorn have shed their leaves, as you would expect given its nearly Christmas! It did however take them to the end of November to do so. The other hawthorn is at the end of this little row of plants and gets more shelter. It has shed a few leaves and has some yellowing leaves but a large amount of green leaves remain on the tree. To look at it you would think it was September not December! Otherwise it seems pretty healthy and seemed to grow well over the year. Just wondering if this is a result of the very mild weather we are having and whether it will do it any harm? Should I just leave it alone and let nature sort itself out? Or is it a sign of a problem with the sapling? Thanks in advance for any advice.