Foliage in Ipswich, MA, USA, 2011

The formation of beautiful foliage requires rapid temperature drop that curtails green chlorophyll while revealing colorful accessory pigments (carotenoids and xanthophylls) without killing the leaves.  It had been unseasonably warm until the first nor'easter on October 29 in Massachusetts, so this year's foliage is not as vivid as people would like to see.

The following series of photos shows the progression of 2011 foliage formation.