Planning tool

USDA Zone and Frost-Date Planner

Compare USDA hardiness-zone temperature bands with local last-frost and first-frost dates so annual vegetable, herb, and flower timing is not reduced to zone alone.

Inputs

USDA hardiness zone

Identifies average annual extreme minimum temperature bands for perennial survival context.

Last frost date

Controls spring direct-sow, indoor-start, and transplant timing for annual crops.

First frost date

Controls fall planting windows and expected season length.

What it returns

• USDA half-zone temperature band context.
• Season length from frost-date inputs.
• Links into regional guides and season-specific catalog paths.

Lookup source decision

Recommended provider

USDA Plant Hardiness Zone Map

Build-time ZIP lookup

ready. Use the official USDA Plant Hardiness Zone Map as the user-facing source and the official OSU PRISM 2023 USDA Plant Hardiness Zone ZIP Code Listings as the build-time browser lookup artifact. Keep the manual USDA ZIP search visible, preserve attribution and caveats, and do not infer frost dates or planting windows from ZIP results.

Lookup artifact

/data/usda-phzm-zip-lookup.json with 39,921 ZIP records.

Artifact dataset

OSU PRISM 2023 USDA Plant Hardiness Zone ZIP Code Listings

Integration rule

Use only a documented API or official USDA/OSU GIS data pipeline for automated ZIP or coordinate lookup; the current ZIP lookup uses the official OSU PRISM ZIP Code Listings artifact.

Hardiness-zone limitation

Hardiness zones describe average annual extreme minimum winter temperature, not last frost dates, first frost dates, soil temperature, or annual vegetable planting windows.

USDA/OSU GIS guardrails

Pipeline status

Status: design-only. Browser lookup uses a committed build-time artifact from official OSU PRISM ZIP listings.

ZIP artifact source

OSU PRISM 2023 USDA Plant Hardiness Zone ZIP Code Listings: https://prism.oregonstate.edu/phzm/data/2023/phzm_us_zipcode_2023.csv

ZIP artifact caveat

ZIP Code listings are not parcel-level hardiness-zone results; local microclimates, elevation, and ZIP boundaries can differ from a garden site.

ZIP artifact boundary

Do not infer last frost dates, first frost dates, or planting windows from the ZIP result.

Data inputs

Use only official USDA/OSU or PRISM GIS data for automated lookup, including the 2023 grid, shapefile, raster, or ZIP-code datasets described by USDA.

Processing

Process GIS data offline or at build time into a small read-only lookup artifact; do not call interactive map requests from the browser.

Attribution

Show USDA-ARS and OSU attribution when presenting data or maps derived from the official GIS datasets.

Frost-date boundary

Return hardiness-zone results separately from frost-date planning; do not infer last frost dates, first frost dates, or planting windows from a zone result.

Result contract

Show the resolved USDA half-zone and average annual extreme minimum temperature band without deriving crop timing. Show USDA-ARS and OSU attribution next to the result whenever derived PHZM GIS data is used. Show ZIP boundary, centroid, and microclimate caveats near the result so gardeners do not treat the ZIP result as parcel-level advice. Keep the manual USDA ZIP search link available as a fallback next to automated results.

Blocked approach

Do not scrape undocumented ArcGIS, iframe, or browser network requests from the interactive USDA map.

Regional guide fallback

• Regional Planting Guides Use the regional guide index when a ZIP result is too broad; 111 source-backed regional guides cover All 50 U.S. states.

Regional timing paths

• Alabama Seasons 25 catalog crop examples
• Alameda East Bay 28 catalog crop examples
• Alaska Short Season 12 catalog crop examples
• Arizona Elevation Bands 30 catalog crop examples
• Arkansas Fall 17 catalog crop examples
• Arkansas Zone C 26 catalog crop examples
• Butte Foothills 22 catalog crop examples
• California Interior Valley 25 catalog crop examples
• Central Florida 10 catalog crop examples
• Central Maryland 25 catalog crop examples
• Central Missouri 11 catalog crop examples
• Central NH 31 catalog crop examples
• Central Oregon Seeds 15 catalog crop examples
• Chicago Area IL 20 catalog crop examples
• Colorado Front Range 8 catalog crop examples
• Colorado Containers 19 catalog crop examples
• Colorado Mountains 25 catalog crop examples
• Connecticut Calendar 30 catalog crop examples
• Contra Costa Interior 18 catalog crop examples
• Delaware Frost 25 catalog crop examples
• East Texas 28 catalog crop examples
• Eastern NC 32 catalog crop examples
• Eastern Oregon Seeds 20 catalog crop examples
• Georgia 17 catalog crop examples
• Georgia Varieties 11 catalog crop examples
• Harris County 34 catalog crop examples
• Hawaii Elevations 13 catalog crop examples
• Idaho Zones 27 catalog crop examples
• Illinois 21 catalog crop examples
• Indiana Frost/Soil 32 catalog crop examples
• Iowa Timing 10 catalog crop examples
• Kansas Calendar 36 catalog crop examples
• Kauai County 19 catalog crop examples
• Kentucky Regions 29 catalog crop examples
• Long Island 18 catalog crop examples
• Louisiana North/South 12 catalog crop examples
• Michigan LP 20 catalog crop examples
• Maine Coast/North 17 catalog crop examples
• Maricopa County 36 catalog crop examples
• Marin Monthly 28 catalog crop examples
• Massachusetts 35 catalog crop examples
• McHenry County IL 28 catalog crop examples
• Middle Georgia 20 catalog crop examples
• Minnesota Soil Temp 33 catalog crop examples
• Mississippi Zones 27 catalog crop examples
• Missouri Varieties 14 catalog crop examples
• Montana Frost Windows 27 catalog crop examples
• Napa County 20 catalog crop examples
• Nebraska Frost/Soil 25 catalog crop examples
• New Jersey Frost 21 catalog crop examples
• New Mexico Zones 17 catalog crop examples
• NYC Area 35 catalog crop examples
• NC Piedmont 17 catalog crop examples
• North Dakota Small Space 16 catalog crop examples
• North Florida 26 catalog crop examples
• North Missouri/Ozark 12 catalog crop examples
• Northern Nevada 20 catalog crop examples
• Northern Wisconsin 32 catalog crop examples
• Central Ohio 32 catalog crop examples
• Oklahoma Fall 18 catalog crop examples
• Oklahoma Planning 22 catalog crop examples
• Orange County Small Space 27 catalog crop examples
• Oregon Coast 27 catalog crop examples
• Oregon Regions 8 catalog crop examples
• Philadelphia Area 34 catalog crop examples
• Pima County 41 catalog crop examples
• Placer County 26 catalog crop examples
• Rhode Island Calendar 31 catalog crop examples
• Rockwall County 28 catalog crop examples
• Sacramento Area 32 catalog crop examples
• San Diego County 25 catalog crop examples
• SLO Cool Season 24 catalog crop examples
• SF/San Mateo 29 catalog crop examples
• Santa Clara County 42 catalog crop examples
• Shasta County Valley 31 catalog crop examples
• Sonoma Planting 39 catalog crop examples
• South Carolina 29 catalog crop examples
• South Dakota Frost/Soil 22 catalog crop examples
• South Florida 22 catalog crop examples
• South Missouri 14 catalog crop examples
• SE Wisconsin 31 catalog crop examples
• Southern Nevada Desert 28 catalog crop examples
• Tennessee Cool Season 6 catalog crop examples
• Tennessee Warm Season 6 catalog crop examples
• Texas Fall 21 catalog crop examples
• Texas Home Garden 27 catalog crop examples
• Travis County 30 catalog crop examples
• Tulare/Kings Valley 29 catalog crop examples
• Upper Midwest 8 catalog crop examples
• Michigan UP 20 catalog crop examples
• Upstate New York 26 catalog crop examples
• Utah Frost Groups 29 catalog crop examples
• Utah Varieties 6 catalog crop examples
• Ventura County 36 catalog crop examples
• Vermont Frost 22 catalog crop examples
• Virginia Zones 27 catalog crop examples
• Walla Walla Inland NW 21 catalog crop examples
• Wasatch Front 31 catalog crop examples
• Washington County Fall 15 catalog crop examples
• Washington County UT 14 catalog crop examples
• Western Washington 23 catalog crop examples
• West Virginia 33 catalog crop examples
• Western NC 40 catalog crop examples
• Willamette Calendar 40 catalog crop examples
• Wisconsin Containers 13 catalog crop examples
• Wyoming Statewide 9 catalog crop examples
• Midwest Native Pollinators 7 catalog crop examples
• Yolo County Spring 9 catalog crop examples
• York County PA 8 catalog crop examples
• York County Seeds 21 catalog crop examples
• Yuma County 38 catalog crop examples

Season paths

• Cool Season Seeds Crops that can fit spring or fall windows
• Warm Season Seeds Crops that need frost-free warmth
• Shoulder Season Seeds Flexible crops between cool and warm windows
• Fall Planting Planner 63 first-frost-window varieties
• Fall-Planting Seeds 63 first-frost-window varieties

Fall-window examples

• Long Island Improved Brussels Sprouts 16 weeks before first frost
• American Flag Leek 14 weeks before first frost
• American Purple Top Rutabaga 12 weeks before first frost
• Golden Acre Cabbage 12 weeks before first frost
• Marketmore 76 Cucumber 12 weeks before first frost
• Snowball Y Cauliflower 12 weeks before first frost

Source basis

• USDA Plant Hardiness Zone Map Official 2023 USDA PHZM site with interactive map and user-facing ZIP Code search
• USDA PHZM Map Creation Explains GIS data ownership, attribution conditions, ZIP finder, and 1991-2020 normals
• OSU PRISM 2023 PHZM GIS datasets Official OSU PRISM page for 2023 PHZM grid, shapefile, KML, and ZIP Code Listing datasets
• OSU PRISM 2023 PHZM ZIP Code Listings CSV Official CSV listing ZIP Code, USDA half-zone, temperature range, and zone title for build-time lookup
• USDA Ag Data Commons 2023 PHZM rasters Official 2023 raster dataset for future GIS-based zone lookup work
• USDA PHZM How to Use the Maps Describes ZIP search, map use, hardiness-zone limits, and microclimate caveats
• UMN planting the vegetable garden Upper Midwest regional timing source
• UMN planting the vegetable garden Minnesota Soil Temp regional timing source
• OSU Extension Planning for the Garden Central Ohio regional timing source
• CSU vegetable planting guide Colorado Front Range regional timing source
• CSU Extension vegetable gardening in containers Colorado Containers regional timing source
• CSU Extension vegetable gardening in the mountains Colorado Mountains regional timing source
• UW Extension Waukesha County Vegetable Garden Planting Schedule SE Wisconsin regional timing source
• UW-Madison Extension Vegetable Varieties for Containers Wisconsin Containers regional timing source
• UW Extension Planting guide for northern Wisconsin Northern Wisconsin regional timing source
• University of Wyoming Extension Growing Vegetables in Wyoming Wyoming Statewide regional timing source
• UVM Extension Master Gardener Planting the Garden Vermont Frost regional timing source
• University of Delaware Cooperative Extension Planning a Vegetable Garden Delaware Frost regional timing source
• Rutgers NJAES Starting Vegetable Seeds Indoors New Jersey Frost regional timing source
• URI Cooperative Extension Rhode Island Planting Calendar Rhode Island Calendar regional timing source
• UConn Connecticut Vegetable Crop Calendar Connecticut Calendar regional timing source
• Cornell Vegetables planting dates for Upstate New York Upstate New York regional timing source
• CCE Suffolk Vegetable Planting Times Guidelines for Long Island Long Island regional timing source
• Cornell Cooperative Extension Harvest NY Planting Guide for the New York City Area NYC Area regional timing source
• University of Idaho Extension Spring Vegetable Planting Guide for Idaho Idaho Zones regional timing source
• MSU Extension Upper Peninsula Michigan Gardening Calendar Michigan UP regional timing source
• MSU Extension Lower Peninsula Michigan Garden Calendar Michigan LP regional timing source
• OSU Extension vegetable gardening in Oregon Oregon Regions regional timing source
• OSU Extension An educator's guide to vegetable gardening Willamette Calendar regional timing source
• OSU Extension Eastern Oregon seed-starting schedule Eastern Oregon Seeds regional timing source
• OSU Extension When to start seeds indoors in central Oregon Central Oregon Seeds regional timing source
• OSU Extension The best vegetables to grow in Oregon's coastal climate Oregon Coast regional timing source
• Clemson Extension planning a garden South Carolina regional timing source
• UA Extension vegetable planting calendar for Maricopa County Maricopa County regional timing source
• Ten Steps to a Successful Vegetable Garden Arizona Elevation Bands regional timing source
• UA Cooperative Extension Yuma County Planting and Harvesting Calendar Yuma County regional timing source
• UA Cooperative Extension Pima County Vegetable Planting and Harvesting Guide Pima County regional timing source
• UF/IFAS Florida Vegetable Gardening Guide Central Florida regional timing source
• UF/IFAS Florida Vegetable Gardening Guide South Florida regional timing source
• UF/IFAS Florida Vegetable Gardening Guide North Florida regional timing source
• UH CTAHR Planting, Harvest Periods and Spacing of Vegetables Kauai County regional timing source
• UH Bulletin 91 Home Gardening in Hawaii Hawaii Elevations regional timing source
• Penn State York County vegetable transplanting guide York County PA regional timing source
• Penn State York County vegetable seed planting guide York County Seeds regional timing source
• Penn State Master Gardeners Philadelphia Planting Guide Philadelphia Area regional timing source
• MU Extension vegetable planting calendar Central Missouri regional timing source
• MU Extension vegetable planting calendar North Missouri/Ozark regional timing source
• MU Extension vegetable planting calendar South Missouri regional timing source
• MU Extension vegetable planting calendar Missouri Varieties regional timing source
• NC State Extension estimated planting dates for the NC Piedmont NC Piedmont regional timing source
• NC State Extension Eastern North Carolina Planting Calendar for Annual Vegetables, Fruits, and Herbs Eastern NC regional timing source
• NC State Extension Western North Carolina Planting Calendar for Annual Vegetables, Fruits, and Herbs Western NC regional timing source
• UGA Extension vegetable planting chart Georgia regional timing source
• UGA Extension Best Garden Vegetable Varieties for Georgia Georgia Varieties regional timing source
• UGA Extension Vegetable Garden Calendar Middle Georgia regional timing source
• Oklahoma State University Extension Oklahoma Garden Planning Guide Oklahoma Planning regional timing source
• OSU Extension fall gardening Oklahoma Fall regional timing source
• Illinois Extension when to plant Illinois regional timing source
• Illinois Extension when to plant Chicago Area IL regional timing source
• Illinois Extension McHenry County vegetable garden planting guide McHenry County IL regional timing source
• Texas A&M AgriLife fall vegetable gardening guide Texas Fall regional timing source
• Texas A&M AgriLife Texas Home Vegetable Gardening Guide Texas Home Garden regional timing source
• Texas A&M AgriLife Travis County Vegetable Garden Planting Guide Travis County regional timing source
• Texas AgriLIFE Extension Service Harris County Vegetable Garden Planting Dates Harris County regional timing source
• Rockwall County Master Gardeners Vegetable Planting Guide Rockwall County regional timing source
• Henderson County Master Gardeners East Texas Vegetable Planting Guide East Texas regional timing source
• UC Master Gardener Contra Costa interior vegetable planting guide Contra Costa Interior regional timing source
• UC Master Gardener Program Time of planting California Interior Valley regional timing source
• UC ANR Cooperative Extension Ventura County Planting Vegetables Ventura County regional timing source
• UC Master Gardeners San Mateo and San Francisco Edible Gardening and Planting Calendars SF/San Mateo regional timing source
• UC Master Gardeners of Santa Clara County Vegetable Planting Chart Santa Clara County regional timing source
• UC Master Gardener Program of Alameda County Growing Vegetables Alameda East Bay regional timing source
• UC Master Gardeners of San Luis Obispo County Cool Season Vegetable Guide SLO Cool Season regional timing source
• UC Master Gardener Program of Sonoma County Vegetable Planting Summary Sonoma Planting regional timing source
• UC Master Gardeners of Placer County Growing Vegetables in Placer County Placer County regional timing source
• UC Master Gardeners of Tulare and Kings County Vegetable Planting Guide Tulare/Kings Valley regional timing source
• UC Master Gardeners of Napa County Vegetable Planting Calendar Napa County regional timing source
• UC Master Gardeners of Sacramento County Vegetable Planting Schedule Sacramento Area regional timing source
• UC ANR The Savvy Sage April Vegetable Planting Guide Yolo County Spring regional timing source
• UC ANR Shasta County Monthly Planting Guide Shasta County Valley regional timing source
• UC Master Gardeners of Orange County Small Spaces Orange County Small Space regional timing source
• UC Master Gardeners of Butte County Foothill Planting Guide Butte Foothills regional timing source
• UC Marin Master Gardeners Edible Garden Monthly Planting & Maintenance Schedule Marin Monthly regional timing source
• UC Agriculture and Natural Resources San Diego County Vegetable Planting Guide San Diego County regional timing source
• NMSU growing zones and planting information for New Mexico home vegetable gardens New Mexico Zones regional timing source
• UAF Cooperative Extension 16 Easy Steps to Gardening in Alaska Alaska Short Season regional timing source
• UMaine Extension planting chart for the home vegetable garden Maine Coast/North regional timing source
• USU suggested vegetable planting dates for Utah Utah Frost Groups regional timing source
• USU Suggested Vegetable Planting Dates For the Wasatch Front Wasatch Front regional timing source
• USU Extension Washington County Vegetable Gardening Washington County UT regional timing source
• USU Extension Washington County Fall Vegetable Garden Calendar Washington County Fall regional timing source
• USU Extension Home Vegetable Garden: Variety Recommendations for Utah Utah Varieties regional timing source
• MSU Extension Can I Grow That Here? Montana Frost Windows regional timing source
• UNR Extension getting started with a vegetable garden Northern Nevada regional timing source
• UNR Extension Becoming a Desert Gardener Southern Nevada Desert regional timing source
• UMD Extension Vegetable Planting Calendar Central Maryland regional timing source
• UNH Extension growing vegetables when to plant your vegetable garden Central NH regional timing source
• UMass Extension Vegetable Planting Chart Massachusetts regional timing source
• WVU Extension Succession Planting West Virginia regional timing source
• MSU Extension Planting Dates Mississippi Zones regional timing source
• Purdue Extension Indiana Vegetable Planting Calendar Indiana Frost/Soil regional timing source
• K-State Research and Extension Vegetable Garden Planting Guide Kansas Calendar regional timing source
• Virginia Cooperative Extension Home Garden Vegetable Planting Guide Virginia Zones regional timing source
• UAEX Arkansas spring and summer vegetable planting dates Arkansas Zone C regional timing source
• UAEX Arkansas fall vegetable planting dates Arkansas Fall regional timing source
• Iowa State University Extension Planting and Harvesting Times for Garden Vegetables Iowa Timing regional timing source
• University of Kentucky Home Vegetable Gardening in Kentucky Kentucky Regions regional timing source
• Alabama Extension Vegetable Seasons in Alabama Alabama Seasons regional timing source
• LSU AgCenter Louisiana Vegetable Planting Guide Louisiana North/South regional timing source
• UT Extension Guide to Warm-Season Garden Vegetables Tennessee Warm Season regional timing source
• UT Extension Guide to Spring-Planted Cool-Season Vegetables Tennessee Cool Season regional timing source
• SDSU Extension Vegetable Gardening in South Dakota South Dakota Frost/Soil regional timing source
• Nebraska Extension Selecting and Preparing Vegetables, Herbs, and Fruit Nebraska Frost/Soil regional timing source
• NDSU Extension Pickin' Patch small-space vegetable gardening North Dakota Small Space regional timing source
• Xerces Native Plants for Pollinators and Beneficial Insects: Midwest Midwest Native Pollinators regional timing source
• WSU Extension Home Vegetable Gardening in Washington Western Washington regional timing source
• WSU Walla Walla Inland Northwest Vegetable Gardening Walla Walla Inland NW regional timing source