How to prepare the bonsai for the winter season. Is there anything to do at all? Yes, there is. First and foremost bonsai needs to be stored away from frosty winds and sun, that may dry them out when the roots are trapped in a frozen soil, not being able to take up water. There are also further small jobs to do.
Start of the winter time is a fine time to make minor adjustments of twigs at deciduous trees, now where the branch structure is easier to see with the leaves shredded. Remaining leaves should be removed by the use of a pair of tweezers or cut off with a sharp scissor without touching the new buds waiting for spring. There is no need for the leaves to overwinter at the branches, because the buds of the tree is already under protection in a greenhouse or other types of winter storage. Keeping leafs at the bonsai may cause harmful fungus stay at the tree, or holding pests that may harm the tree later.
It is wise to remove mosses from the soil surface, so pests are not staying hidden and kept alive in a safe shelter under the moss. It also makes it far easier keeping a safe eye on watering needs during the dormant period.