An option is actually to spray your plants with water. When water freezes, it releases heat (a little counterintuitive, I know, but that's why you have to put water in a cold place to freeze it - you have to take away heat). So, if your plants have a thin layer of water on them that freezes, it actually helps keep them warmer. Additionally, the layer of ice, being a good insulator, will then help keep the plant warmer through the cold spell.
Judith Browning wrote:Hi Kai, I've embedded the video here...