When I look up a plant there are two or three different temp. zones with different temps. How do you tell which temp. is right? Beside the the zone number. I was looking up Aporocactus and the temps were 30, 35, and 10 degrees. (I think thats right on the 10 but that could be the zone.) I tried search but the go or what looks like a folder doesn't always appear on the screen.
Multible temp zones
I don't know. There are a number of plant zone maps, unfortunately when my laptop went to be fixed the web site that explained the (I think 3)different zone maps did not get copied. The temps on DG plant guide is a little strange.
I did find out from my reading that Epis hybridized in Europe can take a lower temp that those over here. Most of the book was in German so don't know why.
I found this when googling about plant hardiness zones: http://www.backyardgardener.com/zone/index.html#what
and, the map where you can click on your state and it shows the different plant hardiness zones in that particular state: http://www.growit.com/zones/
Florida, where I live has 4 different hardiness zones.
Add in the micro zones it get to be a pain. My yard is warmer than those across the street from me and we are about 10 degress warmer that across the river. The east side of my yard is about 5 degress warmer than the west side in winter and cooler in summer. We have lived in this house sense 1954.
Sandy