bonsaiTALK Community - View Single Post - Curling Palmatum leaves...Why?

The symptoms shown on your pics certainly do not look like herbicide damage which would affect, not only a few leaves, but all of them.
The caterpillars did chew part of the leaves and the curling could be due to some of the leaf veins that were damaged by the same caterpillars or another insect.
However, since Japanese maples are not winter hardy in zones 5 and below, the tree should not spend the winter outside even if you try to protect it with a very good mulch. The only way for you to overwinter it, is to keep it in a cold room, or greenhouse, at not more than 40 F until spring.
Furthermore, this tree should not be kept in your house for any length of time. At this time of the year, I suggest that you leave it outside in a well protected place until the leaves fall, because it is resistant to the early frosts which, in fact, are good for its dormancy.
In spring, you should repot the tree in a very well drained bonsai soil which should be watered often to prevent underwatering because root rot is caused only from soils which retain the same water for too long a time around the feeder roots.
Good luck.

13-Oct-2007	#6
ALDEVAUX bonsaiTALK Master Join Date: Mar-2004 Location: St-Hyacinthe, P.Québec Country: CANADA USDA Zone: 4 AHS Heat Zone: ? Posts: 449	The symptoms shown on your pics certainly do not look like herbicide damage which would affect, not only a few leaves, but all of them. The caterpillars did chew part of the leaves and the curling could be due to some of the leaf veins that were damaged by the same caterpillars or another insect. However, since Japanese maples are not winter hardy in zones 5 and below, the tree should not spend the winter outside even if you try to protect it with a very good mulch. The only way for you to overwinter it, is to keep it in a cold room, or greenhouse, at not more than 40 F until spring. Furthermore, this tree should not be kept in your house for any length of time. At this time of the year, I suggest that you leave it outside in a well protected place until the leaves fall, because it is resistant to the early frosts which, in fact, are good for its dormancy. In spring, you should repot the tree in a very well drained bonsai soil which should be watered often to prevent underwatering because root rot is caused only from soils which retain the same water for too long a time around the feeder roots. Good luck.