A word of warning to our members!This cold snap is proving stubborn and care must be taken with your bonsai. Normally an overnight freeze isn't an issue for your trees but for the last few days the soil in the pots has remained frozen during the day as well. This is when problems occur. Some of the trees with fleshier roots are at risk of having their roots burst. Examples of these varieties would be Yew and Trident Maples. Another problem is the wind drying out the branches and foliage on trees. In their frozen state roots aren't capable of replacing the water required. This can lead to major die back in your branch structure. Take steps to protect your trees. Place delicate trees in a green house or other Winter protection. (I'll talk further about this here soon) Bare deciduous trees can be placed into an unheated garage or shed until the cold snap comes to an end. They won't require that much light. Even evergreen bonsai can visit the garage but more natural light will be required as they still photosynthesise.