Zone 4b monthly plan
March planting calendar for zone 4b
These actions use zone 4b's typical frost dates and each crop's extension-sourced planting window.
- Last spring frost
- May 8
- First fall frost
- October 1
- Exact actions
- 36
Get dates for your exact ZIP
Zone averages cover wide areas. Your nearest NOAA station gives a more local frost window.
Source-backed actions
Your March checklist
Search a crop or narrow the list by garden action. Dates are shifted from zone 4b's typical frost window.
Showing 5 of 36 matching actions
Start indoors
36- Ageratum
flower
February 27 to March 13SourceUniversity of Wisconsin-Madison Division of Extension (Wisconsin Horticulture) - March 13 to March 27SourceClemson Cooperative Extension, Home & Garden Information Center
- Bachelors Button
flower
March 13 to March 27SourceNorth Carolina Extension Gardener Plant Toolbox (NC State Extension) - Basil
herb
March 13 to March 27SourceUniversity of Minnesota Extension - Bok Choy
vegetable
March 27 to April 10SourceCornell University Home Gardening
How this checklist is sourced
USDA defines the hardiness zone, NOAA normals provide the typical frost anchors, and each crop's extension source supplies the planting offset. Broad season-only notes are kept on plant profiles because they do not change from one zone page to another.
- USDA Plant Hardiness Zone Map, 2023 by USDA Agricultural Research Service / Oregon State University PRISM Group. the USDA hardiness-zone band.
- U.S. Climate Normals 1991-2020 by NOAA National Centers for Environmental Information. the median spring and fall freeze dates.
Local conditions vary.