What I am seeking is REQUIRED minimum temps for certain plant species. For example, Junipers are often used as bonsai specimens and sold for indoor use. If a Juniper species is listed as Zone 4-9, I understand how much cold it will tolerate. However, how do I determine how much cold is REQUIRED for it to survive? Experience tells me that normal home temps are too warm for it and many other plant specimens that require cold winter temps.
