Planting zones by state are a range, not a single number. Each US state covers three to sixteen of the USDA’s half-zones, depending on how much elevation, coastline and latitude it spans, and the zone that matters for your garden is the one at your ZIP code. The chart below gives every state’s zone range on the 2023 USDA map, the zone most of its ZIP codes are in, and the full split, computed from the same 40,657 ZIP codes behind our planting zone by ZIP code lookup.
A few examples show the spread. Texas runs from zone 7a in Amarillo to 10a in Brownsville and Corpus Christi, with 8b (Dallas, El Paso) the most common. Florida runs from 9a in Pensacola and Tallahassee to 11a in Miami, and Key West is 11b. Michigan runs from 4a in the far Upper Peninsula to 6b in Detroit, but 55% of its ZIP codes are 6a. Ohio barely varies at all: 95% of its ZIP codes are 6a or 6b.
Find your exact zone first
The state chart tells you what to expect; your ZIP code tells you what you have. Two gardens in the same state can be four zones apart.
Enter your US ZIP code for your USDA zone, frost dates & planting calendar.
Planting zones by state: the chart
Each row lists the half-zones that hold at least 1% of the state’s ZIP codes, coldest first, with the share of the state’s ZIP codes in each. Click a zone for its planting calendar and frost dates.
| State | Zones | Most common zone | Zone mix (share of the state's ZIP codes) | ZIP codes |
|---|---|---|---|---|
| Alabama | 7b to 9a | 8a (41%) | 7b 6%, 8a 41%, 8b 41%, 9a 11% | 810 |
| Alaska | 1a to 8b | 5a (12%) | 1a 2%, 1b 4%, 2a 10%, 2b 6%, 3a 7%, 3b 10%, 4a 11%, 4b 10%, 5a 12%, 5b 5%, 6a 2%, 6b 3%, 7a 8%, 7b 6%, 8a 3%, 8b 2% | 266 |
| Arizona | 6a to 10a | 9b (38%) | 6a 1%, 6b 6%, 7a 9%, 7b 3%, 8a 6%, 8b 12%, 9a 10%, 9b 38%, 10a 15% | 488 |
| Arkansas | 7a to 8b | 8a (53%) | 7a 11%, 7b 23%, 8a 53%, 8b 12% | 706 |
| California | 6b to 11a | 9b (34%) | 6b 2%, 7a 2%, 8a 1%, 8b 4%, 9a 9%, 9b 34%, 10a 24%, 10b 21%, 11a 1% | 2,557 |
| Colorado | 4b to 7a | 6a (42%) | 4b 2%, 5a 12%, 5b 36%, 6a 42%, 6b 6%, 7a 2% | 637 |
| Connecticut | 6a to 7a | 6b (61%) | 6a 13%, 6b 61%, 7a 26% | 419 |
| Delaware | 7a to 8a | 7b (92%) | 7a 4%, 7b 92%, 8a 4% | 95 |
| Florida | 9a to 11a | 10a (30%) | 9a 19%, 9b 23%, 10a 30%, 10b 15%, 11a 11% | 1,429 |
| Georgia | 7b to 9a | 8a (42%) | 7b 3%, 8a 42%, 8b 34%, 9a 21% | 903 |
| Hawaii | 11a to 13a | 12b (71%) | 11a 7%, 11b 2%, 12a 18%, 12b 71%, 13a 1% | 137 |
| Idaho | 5a to 7a | 6b (28%) | 5a 13%, 5b 14%, 6a 16%, 6b 28%, 7a 26% | 322 |
| Illinois | 5a to 7a | 6a (41%) | 5a 2%, 5b 29%, 6a 41%, 6b 17%, 7a 11% | 1,550 |
| Indiana | 5b to 7a | 6a (60%) | 5b 6%, 6a 60%, 6b 24%, 7a 9% | 959 |
| Iowa | 4b to 6a | 5a (55%) | 4b 2%, 5a 55%, 5b 41%, 6a 3% | 1,051 |
| Kansas | 6a to 7a | 6b (54%) | 6a 24%, 6b 54%, 7a 22% | 745 |
| Kentucky | 6b to 7b | 7a (77%) | 6b 21%, 7a 77%, 7b 2% | 940 |
| Louisiana | 8b to 9b | 9a (48%) | 8b 27%, 9a 48%, 9b 24% | 714 |
| Maine | 4a to 6b | 5b (32%) | 4a 6%, 4b 6%, 5a 31%, 5b 32%, 6a 23%, 6b 2% | 485 |
| Maryland | 6a to 8a | 7b (61%) | 6a 2%, 6b 1%, 7a 16%, 7b 61%, 8a 20% | 597 |
| Massachusetts | 5b to 7b | 6b (42%) | 5b 8%, 6a 23%, 6b 42%, 7a 22%, 7b 5% | 679 |
| Michigan | 4a to 6b | 6a (55%) | 4a 1%, 4b 3%, 5a 12%, 5b 9%, 6a 55%, 6b 19% | 1,149 |
| Minnesota | 3b to 5a | 4b (38%) | 3b 13%, 4a 21%, 4b 38%, 5a 27% | 981 |
| Mississippi | 7b to 9a | 8b (57%) | 7b 4%, 8a 29%, 8b 57%, 9a 9% | 530 |
| Missouri | 5b to 7b | 6b (46%) | 5b 3%, 6a 19%, 6b 46%, 7a 27%, 7b 5% | 1,149 |
| Montana | 3b to 6a | 4b (33%) | 3b 6%, 4a 18%, 4b 33%, 5a 28%, 5b 8%, 6a 7% | 403 |
| Nebraska | 5a to 6a | 5b (48%) | 5a 19%, 5b 48%, 6a 33% | 617 |
| Nevada | 5a to 9b | 9b (23%) | 5a 2%, 5b 4%, 6a 5%, 6b 11%, 7a 19%, 7b 10%, 8a 1%, 8b 6%, 9a 19%, 9b 23% | 227 |
| New Hampshire | 4a to 6a | 6a (42%) | 4a 2%, 4b 4%, 5a 21%, 5b 31%, 6a 42% | 276 |
| New Jersey | 6b to 8a | 7a (48%) | 6b 11%, 7a 48%, 7b 40%, 8a 2% | 721 |
| New Mexico | 5b to 8b | 7b (25%) | 5b 4%, 6a 15%, 6b 16%, 7a 22%, 7b 25%, 8a 13%, 8b 5% | 423 |
| New York | 4a to 7b | 6a (23%) | 4a 1%, 4b 5%, 5a 7%, 5b 21%, 6a 23%, 6b 15%, 7a 5%, 7b 23% | 2,146 |
| North Carolina | 7a to 9a | 8a (59%) | 7a 6%, 7b 17%, 8a 59%, 8b 15%, 9a 2% | 1,070 |
| North Dakota | 3b to 4b | 4a (78%) | 3b 13%, 4a 78%, 4b 9% | 407 |
| Ohio | 6a to 7a | 6b (55%) | 6a 40%, 6b 55%, 7a 4% | 1,411 |
| Oklahoma | 6b to 8a | 7b (60%) | 6b 2%, 7a 24%, 7b 60%, 8a 14% | 760 |
| Oregon | 6a to 9b | 8b (41%) | 6a 6%, 6b 13%, 7a 8%, 7b 4%, 8a 3%, 8b 41%, 9a 24%, 9b 2% | 468 |
| Pennsylvania | 5b to 7b | 6b (36%) | 5b 4%, 6a 25%, 6b 36%, 7a 28%, 7b 7% | 2,159 |
| Puerto Rico | 11b to 13b | 13a (57%) | 11b 1%, 12a 3%, 12b 23%, 13a 57%, 13b 15% | 175 |
| Rhode Island | 6b to 7b | 7a (52%) | 6b 47%, 7a 52%, 7b 1% | 90 |
| South Carolina | 8a to 9a | 8b (49%) | 8a 38%, 8b 49%, 9a 11% | 530 |
| South Dakota | 4a to 5b | 4b (48%) | 4a 6%, 4b 48%, 5a 44%, 5b 2% | 382 |
| Tennessee | 7a to 8a | 7b (70%) | 7a 14%, 7b 70%, 8a 16% | 781 |
| Texas | 7a to 10a | 8b (38%) | 7a 4%, 7b 3%, 8a 13%, 8b 38%, 9a 22%, 9b 16%, 10a 4% | 2,582 |
| Utah | 5b to 8b | 6a (32%) | 5b 10%, 6a 32%, 6b 17%, 7a 17%, 7b 19%, 8a 2%, 8b 3% | 339 |
| Vermont | 4a to 5b | 5a (57%) | 4a 4%, 4b 24%, 5a 57%, 5b 15% | 307 |
| Virginia | 6b to 8b | 7b (43%) | 6b 3%, 7a 32%, 7b 43%, 8a 17%, 8b 5% | 1,202 |
| Washington | 6a to 9a | 8b (37%) | 6a 2%, 6b 13%, 7a 18%, 7b 4%, 8a 7%, 8b 37%, 9a 18% | 696 |
| Washington, DC | 7a to 8a | 8a (83%) | 7a 1%, 7b 16%, 8a 83% | 260 |
| West Virginia | 6a to 7a | 7a (49%) | 6a 7%, 6b 43%, 7a 49% | 847 |
| Wisconsin | 4a to 6a | 5b (30%) | 4a 9%, 4b 28%, 5a 29%, 5b 30%, 6a 5% | 889 |
| Wyoming | 4a to 5b | 5a (56%) | 4a 5%, 4b 24%, 5a 56%, 5b 15% | 191 |
The “Zones” column ignores zones that hold less than 1% of a state’s ZIP codes. Those are usually a handful of ZIP codes on a mountaintop, a valley floor or a coastal point, and a few are artifacts of where the ZIP code’s center point falls. Zones 1a to 2b exist only in Alaska and have no planting calendar on this site; every other zone in the chart links to one.
How to read the chart
A USDA zone is a 10°F band of the average coldest winter night, split into a colder “a” half and a warmer “b” half 5°F wide. The 2023 map is built from 1991 to 2020 weather data at 13,625 stations, interpolated to a grid about half a mile across, so a zone line can run down the middle of a county. The full zones chart has the winter low in °F and °C, typical frost dates and season length for every half-zone, and USDA planting zones explained covers what a zone does and does not tell you.
The share column counts ZIP codes, not land area or people. That makes it a fair picture of where gardens are, since ZIP codes follow population, but it understates empty high country. Most of Wyoming’s land is colder than its ZIP codes suggest, and most of Nevada’s ZIP codes are in Las Vegas and Reno, not on the ranges between them.
The most common zone in a state is a starting point, not a planting date. Within one zone, the NOAA frost data for the 100 largest cities shows median first frost dates that differ by two or three weeks, because a zone measures the coldest night of winter, not when spring and fall frosts arrive.
States that span the most zones
Alaska is in a class of its own: 16 half-zones from 1a to 8b. Fairbanks is 3b with pockets of 2a and 2b, Anchorage is mostly 5a, and the panhandle towns of Juneau (7a) and Ketchikan (7b) are as mild as Virginia, because the Pacific keeps their winters wet rather than cold.
California covers 9 zones at 1% or more. The Central Valley cities are 9b (Sacramento, Fresno, Bakersfield), the coast is 10a to 10b (San Francisco and Los Angeles are 10b), the San Diego coast reaches 11a, and the Sierra towns of Truckee and South Lake Tahoe are 6b. That is 34% of the state’s ZIP codes in 9b alone, and 79% in 9b to 10b.
Arizona and Nevada do the same thing with elevation instead of ocean. Phoenix is 9b to 10a and Yuma 10a, while Flagstaff, 7,000 feet up, is 6a. Nevada splits between Las Vegas (9a to 9b) and Reno (7a to 7b), with colder high desert towns in between.
Texas spans 7 zones and has more ZIP codes (2,582) than any other state. The Panhandle is 7a to 7b (Amarillo, Lubbock), the Dallas and Fort Worth area and El Paso are 8b, Austin and San Antonio 9a, Houston 9b, and the coast from Corpus Christi south is 10a.
New York surprises people: 8 zones, from 4a in the Adirondacks (Lake Placid) to 7b in New York City. Buffalo and Rochester are 6b thanks to Lake Erie and Lake Ontario, while Albany and Syracuse are 6a. The city and the upstate snow belt are three full zones apart.
States with one dominant zone
At the other end, four places have 75% or more of their ZIP codes in a single half-zone: Delaware (7b, 92%), Washington, DC (8a, 83%), North Dakota (4a, 78%) and Kentucky (7a, 77%). Ohio, Tennessee, Kansas, Nebraska, Louisiana, South Carolina, West Virginia, Connecticut and Rhode Island all fit inside three half-zones. In these states the most common zone is a reasonable default, and a statewide planting calendar is roughly right.
The states people ask about most
Florida (9a to 11a). The panhandle and north Florida are 9a to 9b (Pensacola, Tallahassee, Jacksonville), Orlando and Tampa are 10a, Fort Myers and West Palm Beach 10b, and Miami 11a, and the Keys 11b. Florida’s main vegetable season is fall through spring, and in south Florida the summer, not the winter, is the off-season. The zone 10a page has the calendar for the most common Florida zone.
Texas (7a to 10a). See above. The single most useful thing a Texas gardener can know is that Houston’s last frost (NOAA median February 13) and the zone 7a average that applies around Amarillo (about April 10) are eight weeks apart. Use the zone 8b page as the statewide middle and your ZIP code for the rest.
Michigan (4a to 6b). The Lower Peninsula south of Grand Rapids and Lansing is 6a, Detroit and its suburbs 6b, the north of the Lower Peninsula 5b to 6a (Traverse City is mostly 6a), and the Upper Peninsula 4a to 5b (Marquette 5b, Sault Ste. Marie 4b). Lake Michigan moderates the west coast enough that fruit growers cluster there.
Ohio (6a to 7a). 55% 6b and 40% 6a. Columbus, Cincinnati, Toledo and Dayton are all 6b; parts of Cleveland’s lakeshore are 7a. With a last frost around mid to late April, tomatoes go out in the first week of May almost everywhere in the state.
North Carolina (7a to 9a). 59% of ZIP codes are 8a, including Charlotte, Raleigh and Greensboro. Asheville is 7b, the high mountain towns like Boone are 6b to 7a, and Wilmington on the coast is 8b.
Pennsylvania (5b to 7b). Philadelphia is 7b, Harrisburg and the southeast 7a, Pittsburgh 6b to 7a, Scranton and State College 6b, and the northern tier 5b to 6a.
Hawaii (11a to 13a). 71% of ZIP codes are 12b, including all of Honolulu. Upcountry Maui (Kula) and Kauai’s Lihue are 12a, and the Big Island’s higher towns (Volcano, Waimea and one of Hilo’s two ZIP codes) are 11a. Hawaii’s planting calendar is set by rain and elevation rather than frost; the zone 12b page covers the year-round season.
What to do with your state’s zone
Use the zone to choose perennials, shrubs and trees: a plant tag that says “hardy to zone 6” means it survives a zone 6 winter. For vegetables, the zone is mainly a shortcut to your frost dates, and the frost dates set the calendar. Look up your ZIP, open your zone’s page for the planting calendar, and check the last frost date guide for what can go out before it. If you are planning this winter, the January planting guide lists what to start indoors and sow outside in each zone, and what changed on the 2023 map explains why your state may have shifted half a zone since your last seed catalog.
Methodology
The chart is computed at build time from 40,657 US ZIP codes, each assigned the USDA 2023 hardiness zone at its center point (the same data as the lookup on the home page; the ZIP list comes from the frostline project’s gazetteer and the zones from the USDA 2023 map via the PRISM-based phzmapi service). Shares are counts of ZIP codes, not area or population. Zones holding less than 1% of a state’s ZIP codes are left out of the range so that a single misplaced ZIP code does not stretch it. What this does not measure: microclimates inside a ZIP code, elevation differences within one ZIP code (large in the mountain West), and any zone change since the 2023 map was published.