All bonsai should be dormant by now. In colder areas they will have been put in cold frames, or other storage for the winter.
Location: Guard against any and all of Nature’s changeable weather conditions.
Watering: The same rule applies here as last month. Watch watering under frozen conditions. If soil is kept too wet the pot may crack.
Trimming amd training: Can be done under caution.
Transplanting: Only bare-root nursery stock can be transplanted in a mixture of sand and very little soil. Do not pot any bare-root until spring.
Grafting: December, January, and February are the best months for grafting conifers, for this is the coldest season and the trees are completely dormant. At this time there is no pitch to isolate scion from understock.
Miscellaneous: It is a good time to collect native materials in the Southern states.
- Water as needed – which means checking your Bonsai soil daily to see or feel if your soil is drying out. A lot of this will depend on the humidity of the surroundings and how active your Bonsai’s growth is this time of year.
- Check for insects or disease continuously. This comment is not meant to cause paranoia. Its focus is for you to be observant to the overall health and well being of your Bonsai. You can tell if there is a yellowing and falling off of leaves. You can tell if there is a change in the color of the foliage or needles. These are indications that something is changing … some of this is natural and some of this can be from spider mites or other critters. Just be mindful that, as with us, when there is a change in appearance it can be a normal thing or a thing that is the first indication of a larger problem that is just in the formative stages.
- As to light – For deciduous Bonsai: this is not a problem as there are bare of leaves this time of year. For evergreen Bonsai – this is a problem. December 21 is the shortest day of the year. Meaning there is little natural light during the month of December. For some Bonsai with few leaves this will not be a problem. But for most evergreen Bonsai this is a problem. You may need to give your Bonsai some artificial light to help it through this low light period. Plant lights can be purchased at most large Grocery stores in their light bulb departments or at the large box home improvement warehouses in either incandescent or fluorescent. Fluorescent or incandescent lights will both do the same basic work for your Bonsai. You need a light fixture for either and that may make your mind up as to which one. Just remember incandescent (or light bulbs) do emit a lot of heat. Fluorescents do not, but have larger fixtures to contend with.