Reply To: autumn colours Kisetsu-en Shohin Bonsai Europe › FORUM › Bonsai › autumn colours › Reply To: autumn colours 19. August 2021 at 21:38 #52752 albekKeymaster This is most likely because we had a warmer and dryer period than usual. Especially spring was cold the reaction might be stronger. This make some try trees withdraw the green chlorophyll earlier to protect them from being exhausted.