Where can I find information on the weather and temperature resistance of herbs, including rosemary, thyme, and parsley?
Certified GKH Gardening Expert
You can look up the gardening zones in which each herb does best to find out about their heat and cold resistance. Different countries have different gardening zone systems, but here are the United States (USDA) ones:
The specific information about the three herbs you mention is as follows:
Parsley: USDA zones 6-9
Rosemary: zones 8-11
Thyme: zones 4-9
Here is some more information: