Germinating European Mandrake Seed

I just purchased some Mandrake seed from your great company and I was wondering would it be better to try germination in the frig or outside? Currently our night time temperatures run from 28-40 degrees Fahrenheit and our daytime temps run anywhere from 55-75 degrees Fahrenheit.
Any other tips you have would be greatly appreciated. I live in the mountains of Southern California, USA (over 6,000 feet above sea level) and although the USDA map lists us as an 8 we are really zone 6-7.

Putting your seeds outside might prolong the germination for two to three years. Norman Deno found that starting this seed at 70 degrees gave zero germination with and without light or gibberellic acid. However, by wrapping the seed into a damp sheet of paper towel and placing this into a clean plastic bag folded over at the open end but not sealed, and subjecting it to 3 months of 5 degrees Celsius (40 degrees Fahrenheit), followed by three months of 20 degrees Celsius (70 degrees Fahrenheit), then repeating the series of temperatures, he got 4 out of six seeds to germinate. Plant the germinated seeds and continue the others in the chilling and warming, but be sure to check the seeds about once a week and change the damp paper if it gets mouldy.