Zone 3b Planting Calendar
Zone 3b is the warmer half of Zone 3. See also: Zone 3 full calendar
Last updated: May 15, 2026Zone 3b Climate Facts
Last Spring FrostMay 8
First Fall FrostSep 22
Growing Season137 days
Plants Available38 varieties
All Plants for Zone 3b
📚 Data Sources
Frost dates: NOAA Climate Normals 1991–2020, National Centers for Environmental Information.Hardiness zones: USDA Plant Hardiness Zone Map, Agricultural Research Service.
Growing requirements: Cooperative Extension Services — NC State, Penn State, University of Florida IFAS.
Companion planting: Cornell University Cooperative Extension.
Data compiled from public agricultural sources. Always verify with your local extension office for micro-climate adjustments.