Calendar comparison
ZIP code planting calendar vs hardiness zone calendar
A hardiness zone calendar is a broad starting point. A ZIP code planting calendar narrows vegetable timing with the representative frost station, first and last frost estimates, and crop-specific rules.
Same zone, different planting date
USDA zone 8a covers both Atlanta, GA and Raleigh, NC
A zone-only calendar gives them the same wide April window. GrowZone splits them by frost station.
| Zone-only calendar | GrowZone by ZIP |
|---|---|
| Zone 8a calendar: transplant tomatoes sometime in April. | Atlanta 30301 transplant Apr 5 (atlanta-hartsfield, Mar 29 last frost) vs Raleigh 27601 transplant Apr 17 (Apr 10 last frost), a 12-day gap inside the same zone. |
When to use each calendar
Use a zone calendar to understand winter cold risk and browse broad regional timing. Use a ZIP calendar when you need the actual start-indoors, transplant, or direct-sow week for a crop.