Most plants that live where there is a a real season called "winter" have what botanists call 'chilling requirement' A certain number of hours/days below a certain temperature. Sometimes this is expressed as a smaller number and a temperature range.
Chilling requirements are a survival mechanism to prevent the tree from breaking bud during a warm spell in winter.
E.g. coastal sitka spruce have a chilling requirement of 300 hours below 40 F. For interior Englemann spruce that requirement is 1500 hours. If you plant Englemann spruce in a zone 8 climate it won't break bud it's second year.
The chilling requirement is why many types of bonsai need to overwinter outside.
I've been unable to find chilling requirements for more than a handful of plants.
Does anyone know of a source for chilling requirements?
It would seem that given the hardiness zone of a plant, that a first approximation of chilling requirement might be calculated. Something like K * (November_ave + December_ave ... April_ave) where
the averages are average temperature. K is a constant, and months with averages above N are ignored.
