1. Can you dig them up before we have a hard frost? Would like to get them prepared for winter quite soon. 2. What is the proper way to divide the tubers? 3. Should they be rinsed in an amonia a wash? 4. How dry should the tubers be before placed in vermiculite? Last, any other information you can provide would be mighty helpful. Thank you. Ask an Expert is mighty wonderful.
It is recommended that you wait until the foliage has died back from frost before digging up your dahlias. Rinse with a hose, then dry 1-3 days out of direct sunlight. See link below for full details. http://www.extension.umn.edu/garden/yard-garden/flowers/storing-tender-bulbs/ When dividing tubers, cut with a sharp knife and ensure each division has an eye. Division can be done in spring or fall. https://blog.northerngardener.org/how-to-dig-and-divide-dahlia-tubers/ See below for a link with general info about growing dahlias in Minnesota. http://www.extension.umn.edu/garden/yard-garden/flowers/growing-dahlias/