Christmasy cotoneaster

I love the vivid red leaves that form on Cotoneaster towards the end of the year caused by high levels of anthocyanins and sugars at a time when chlorophyll production has ceased. Apparently a cold snap can trap sugars in the leaves so the best leaf colour tends to be in autumns when there is a cold spell in October/November followed by a warmer period, a pattern frequently experienced in New England and Canada.