Data status

Where zone and frost data are verified, which Extension crop calendars are referenced, and what gaps remain by state.

Hardiness zones come from the 2023 USDA Plant Hardiness Zone Map ZIP listings. Frost dates are place-backed nationwide from NOAA NCEI Climate Normals joined to each ZIP. Extension crop calendars are applied only when geography can be cited without inventing region boundaries. Rows marked frost-only still get reliable zone and frost anchors; outdoor crop windows use catalog frost-relative offsets until a joinable Extension calendar is wired.

Last reviewed 2026-08-20. 26 jurisdictions have a place-backed Extension crop calendar (full or partial). Bracket numbers link to data sources. Full gap notes live in the planner when you look up a ZIP.

Coverage status by U.S. state and territory: USDA zone verification, Extension crop calendar references, and known gaps
State	Zones verified	Frost verified	Extension crops	Sources	Gaps
AlabamaAL	Yes	Yes	Place-backed (partial) ZCTA→county → USDA Ag Statistical District roster → North / Central / South	[14][35]	Counties missing from the digitized Ag District roster stay frost-relative
AlaskaAK	Yes	Yes	Frost only	—	No statewide Extension vegetable crop×region calendar wired; frost-relative offsets only
American SamoaAS	No	No	Frost only	—	No Extension planting calendar found for this territory
ArizonaAZ	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
ArkansasAR	Yes	Yes	Place-backed (partial) Statewide (all AR ZIPs) — UAEX MP422 Zone C baseline outdoor windows	[20]	Frost zones A–E maps cut counties; spring ≠ fall; zone-specific offsets not wired
CaliforniaCA	Yes	Yes	Place-backed (partial) ZCTA→county → UC Table 13.2 partial (Monterey-north coast / SLO-south coast / Imperial)	[21][35]	Interior valleys, Sierra, foothill, and high-desert counties unmapped; Coachella Valley not assigned to a full county
ColoradoCO	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
ConnecticutCT	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
DelawareDE	Yes	Yes	Place-backed Statewide (all DE ZIPs)	[30]	None noted
District of ColumbiaDC	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
FloridaFL	Yes	Yes	Place-backed (partial) SFYL gardening-region county map (preferred); else ZCTA lat vs SR 40/70	[26][35]	Six bisected counties use majority-fill regions on the SFYL map (e.g. Duval→central, Marion→north)
GeorgiaGA	Yes	Yes	Place-backed (partial) NCEI last-spring frost → UGA C943 North / Middle / South week offsets	[19][4]	Middle Georgia baseline only; coastal and mountain microclimates may differ from C943 belt proxy
GuamGU	No	No	Frost only	—	No Extension planting calendar found for this territory
HawaiiHI	Yes	Yes	Frost only	—	No statewide Extension vegetable crop×region calendar wired; frost-relative offsets only
IdahoID	Yes	Yes	Place-backed (partial) USDA zones 3–4 / 5–6 / 7 → BUL 965 Table 1 columns	[28][1]	USDA zones outside 3–7 stay frost-relative (BUL 965 columns cover 3–7 only)
IllinoisIL	Yes	Yes	Place-backed (partial) NCEI last-spring frost → Illinois Extension North / Central / South bands	[12][4]	Region bands follow ISWS frost-map midpoints cited on When to Plant, not county polygons
IndianaIN	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
IowaIA	Yes	Yes	Place-backed (partial) ZCTA→county → NASS crop reporting district roster → ±1 week from central Iowa baseline	[13][35]	Counties missing from the NASS district roster stay frost-relative
KansasKS	Yes	Yes	Place-backed (partial) Statewide (all KS ZIPs) — MF315 primary bar; MF312 tomato SE / E–C / NW via NCEI last-spring frost	[11]	Non-tomato crops use MF315 statewide primary bar only (no county-level MF312 splits)
KentuckyKY	Yes	Yes	Place-backed (partial) ID-128 Fig. 20.8 high-confidence, non-split counties only	[33][35]	About 36 split or low-confidence Fig. 20.8 counties remain unmapped
LouisianaLA	Yes	Yes	Place-backed USDA 8a/8b → North; 9a/9b → South (P3761-A / Pub. 1980)	[31][1]	None noted
MaineME	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
MarylandMD	Yes	Yes	Place-backed (partial) NCEI frost-free growing-season length → early / central / late Maryland band (±1–2 weeks)	[18][4]	Band shift uses growing-season length proxy, not county polygons or Western Maryland frost maps
MassachusettsMA	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
MichiganMI	Yes	Yes	Place-backed Upper Peninsula = 15 UP counties; else Lower Peninsula + cited zone week offsets	[34][2]	Okra is not listed on the MSU LP/UP gardening calendars
MinnesotaMN	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
MississippiMS	Yes	Yes	Place-backed ZCTA→county → P3616 Fig. 2 Areas 1–5 (splits via NCEI frost)	[24][35]	None noted
MissouriMO	Yes	Yes	Place-backed ZCTA→county → G6201 Fig. 1 North / Central / South	[25][35]	None noted
MontanaMT	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
NebraskaNE	Yes	Yes	Place-backed (partial) NCEI last-spring frost → UNL Eastern / Central / Western regional tables	[17][4]	Region bands follow UNL frost-map prose, not county polygons
NevadaNV	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
New HampshireNH	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
New JerseyNJ	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
New MexicoNM	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
New YorkNY	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
North CarolinaNC	Yes	Yes	Place-backed ZCTA→county → Fig. 9–1 Mountains / Piedmont / Coastal Plain (majority fill) → Western / Central / Eastern AG-756 calendars	[7][8]	12 counties are split on Fig. 9–1; majority/primary fill is used (same convention as FL SFYL / MO G6201)
North DakotaND	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
Northern Mariana IslandsMP	No	No	Frost only	—	No Extension planting calendar found for this territory
OhioOH	Yes	Yes	Place-backed (partial) USDA 5b / 6a / 6b week offsets on Zone 6a calendar base	[27][1]	Ohio USDA zones outside 5b/6a/6b stay frost-relative for this calendar
OklahomaOK	Yes	Yes	Place-backed (partial) ZCTA→county → OHCE Extension district roster → SE / NE / West–South / West–North quadrants	[15][35]	Counties missing from the OHCE district roster stay frost-relative
OregonOR	Yes	Yes	Place-backed (partial) ZCTA→county → EC 871 four growing regions (visual map digitization)	[9][10][35]	Three split counties use majority-fill on the EC 871 map (Douglas, Lane, Wasco)
PennsylvaniaPA	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
Puerto RicoPR	Yes	Yes	Frost only	—	No Extension planting calendar found for this territory
Rhode IslandRI	Yes	Yes	Place-backed Statewide (all RI ZIPs)	[29]	None noted
South CarolinaSC	Yes	Yes	Place-backed ZCTA→county → Clemson Piedmont / Coastal Plain lists	[23][35]	None noted
South DakotaSD	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
TennesseeTN	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
TexasTX	Yes	Yes	Place-backed (partial) USDA↔Texas Table 3 → Fall Guide Regions I–V; spring Table 8 weeks after NCEI frost-free date	[32][1]	Spring dates use Table 8 frost-relative weeks, not a separate regional spring table
U.S. Virgin IslandsVI	No	No	Frost only	—	No Extension planting calendar found for this territory
UtahUT	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
VermontVT	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
VirginiaVA	Yes	Yes	Place-backed VA + USDA half-zones 6a–8b (SPES-673 tables 2–4)	[3]	Virginia ZIPs outside USDA zones 6a–8b use frost-relative offsets for crop tables
WashingtonWA	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
West VirginiaWV	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets
WisconsinWI	Yes	Yes	Place-backed (partial) NCEI last-spring frost → UW A1989 Southern baseline with Central / Northern week offsets	[16][4]	Lakeshore week adjustments from A2801 are not applied separately
WyomingWY	Yes	Yes	Frost only	—	No place-matched Extension crop outdoor calendar wired yet — outdoor dates use frost-relative catalog offsets