True colors shining through this fall

Financial market meltdowns. Painfully high gas and food prices. Tom Brady's knee. OK, maybe it won't be a perfect autumn, but at least you won't be able to blame Mother Nature.

Horticulturists and arborists say the weather conditions over the last few months have conspired in Greater Boston's favor and are promising what could be a fall foliage season for the ages. "It's just been absolutely perfect," said Scott LaFleur, director of horticulture for the New England Wild Flower Society, headquartered in Framingham. "This is setting the stage for an incredible fall."

LaFleur and other tree experts say the groundwork for the promising foliage season was laid this summer, when the same wet weather that dampened Cape Cod vacations also created a region full of well-hydrated trees.

The rains mostly stopped after Labor Day. Then the nights turned just chilly enough to encourage the trees to start transforming the sugar in their sap into anthocyanin (a leaf pigment) without producing the kind of early frosts that can dull color.

The end of photosynthesis is key, LaFleur said, because foliage trees don't so much change their color as reveal it. Yellow and orange pigments are always present in leaves but are overpowered during the warmer months by green chlorophyll.

Foliage season in the Boston suburbs usually begins in early October and peaks a week or two before Halloween. This year, the experts said, the season could be both more brilliant and longer thanks to the favorable weather, perhaps as long as a month.

RALPH RANALLI