Freezing weather and watering!
We’re having a week of overnight freezes here in Portland, Oregon following a few days of bright sun and drying winds. The pots are—for once—drying out.
One of the most dangerous things about freezing weather for bonsai is dry soil. Pots breaking is truly a secondary concern. Bad root damage can occur if there is not water in the pot to insulate the roots when it freezes. Otherwise you get a double whammy—freeze dried roots.
So get out your hoses…or spot water with a can…and protect those roots. If you have frequent freezing in winter storage, then watering should be more frequent than you might think. Freezing has one other side effect…it dries out the soil.
In Japan, Mr. Suzuki would have us try to thaw out the bonsai each winter day a bit, so that we could water them. This is a bit contrary to what we hear in the west. But it makes sense.