The change in seasons from hot and dry (July, August, September) to cool/cold/wet (October, November, December) to very cold and wet (January, February, March) to mild, warm and sunny (April, May, June) once, a long time ago, seemed to be moderately predictable. To my eye this really started to shift about 10 years ago.The new and emerging weather systems are far less predictable and the peaks and valleys are higher and lower.
This climb in magnitude and reduction of cycle times is common in physical systems undergoing rapid alteration. The meaning of all this variability for bonsai is not yet clear. Hot is getting hotter, wet is wetter, cold is colder and the wind is blowing harder. Each of these activities in our environment re- quires us to recalibrate our responses to keep our small potted trees strong and healthy.
One of the many things I love about bonsai is its focus on nature and how she works. Every time I go outside to look at the nursery I am conscious of the space we occupy. I notice the temperature, humidity, angle of the sun, wind, bugs, diseases, soil conditions, growth patterns, the plant/earth dialogue as it is played out in the lives of my trees. This awareness of ones surroundings is somehow being lost as many of our people, young and old, spend the great majority of their time indoors looking closely at small electronic devices. The world spins around them without their attention. I think the outcome of this situation is not going to be pretty.
Anyway, keep your trees from drying out. Don’t over water but don’t let the bonsai pots become dry. If the pot is dry and there is a hard freeze the roots are full of water and the soil is dry so when the root freezes there is no countervailing force to keep it from bursting. If the pot and the root are both moist then freezing happens equally on both sides of the cell wall and things remain stable.
Pick off any scale insects that are over wintering on your bonsai, now is a good time to find them and they come off easily. If you have some sooty mold (your trunk and branches will become dark) it is a good time to gently use power washer or hard hose nozzle with a tooth brush to remove it. Once it is washed off you can apply an agricultural oil (Neem, volck or some other) to stop it from coming back. Now is a good time to do heavy trimming, removing branches that don’t enhance the design. Being able to see into our deciduous trees lets us apply styling wire with ease; so go ahead and do that. It was 18 degrees at 7am here three days ago. We will discuss repotting in January.