I’ve had a few worried people asking me “Do bonsai lose their leaves in the winter?“. This depends on what type of bonsai tree that it is. If it has got leaves and it’s kept outdoors, the chances are that it’s a deciduous type tree or bush and therefore it will lose it’s leaves.
What you must remember is that bonsai are just small trees or shrubs. Because of this, they will act in exactly the same way as other trees around at this time of the year. Most will become dormant and drop their leaves until the weather warms up again in spring. Even needle type trees such as pines or junipers will become dormant and stop growing.
The only difference is that the needles (in most cases) will stay on the tree. There are always exceptions to the rule where the leaves will stay on and the needles will fall off. It’s best to identify your bonsai to find out what it will do this year.