Chestnut leaves!

American chestnut leaves on March 14, 2012

I keep a few little American chestnuts (Castanea dentata) growing in pots for school visits and other demonstrations.  After two 80-degree days this week, I noticed today that one of the little chestnuts had leaves!

Trees in pots are more influenced by ambient temperatures.  The temperature extremes in regular soil are buffered, whereas potted soil can be warmed almost uniformly.  So, for the same reason that potted plants' roots are vulnerable to extreme cold, this little tree's leaves emerged as a response to warming, presumably triggered by a drop in abscisic acid and a corresponding increase in gibberellin levels.