| What kinds of perennials would look good & come back after winter in a window box? |
| Unfortunately, in my experience your winter temperatures are too cold for plants to survive in window boxes. The reason is that their roots are not as well insulated as they would be if planted in the ground, so not only are they exposed to extreme cold but also to oscillating temperatures. Both of these, as well as drying out in winter, are very stressful on plants. I'm sorry I can't be more encouraging. |
