Zone 3b is a zone in the USDA Hardiness climate zone rating system. The USDA Hardiness system can be useful to gardeners in establishing if certain plants are suitable for your garden's microclimate and was originally devised by the US department of agriculture. There are currently 282 gardens being tracked on Folia that are in USDA Zone 3b.

Some popular plants that tend to grow very well in this zone include Carrot, Bean, Potato, Broccoli, Chili pepper, Sweet pepper, Cucumber, Tomato, Sunflower and Winter squash.

Some locations recently identified as being in this zone include Soapstone-Buffalo Mine, Alaska (United States), Edmonton (Canada), Edmonton (Canada), Teton Valley Idaho (United States), Calgary (Canada), Tunica (United States), Edmonton (Canada), Aurora (United States), Naples (United States), Laurentians (Canada), Edmonton (Canada), Lethbridge (Canada), Cold Lake (Canada), Jericho, VT (United States), Edmonton (Canada), Eau Claire (United States), Ottawa (Canada), Ottawa (Canada), Lethbridge (Canada), mount Washington (United States), (Canada), Altona (Canada), Edmonton (Canada), Winnipeg (Canada), Hinesburg (United States), Edmonton (Canada), Bozeman, MT (United States), Palmer, Alaska (United States), Atlanta (United States) and Rexburg, Idaho (United States).

If you are in 3b, lowest temperatures in your garden should be around -37°C [-35°F] to -34°C [-29°F].

The corresponding Sunset zone for 3b is approx. A1.