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Find your USDA zone by ZIP code — see what thrives, what struggles, and how to garden smarter in your climate
Based on the 2023 USDA Plant Hardiness Zone Map (1991–2020 data)
Your USDA plant hardiness zone is the single most important number for choosing perennials, trees, shrubs, and vines that will survive your winters. Once you know your zone, you stop guessing and start gardening with confidence — choosing plants that are built for your climate and avoiding costly failures.
The USDA Plant Hardiness Zone Map divides the US into 13 zones based on the average annual extreme minimum winter temperature. Each zone covers a 10°F range. Lower zone numbers mean colder winters; higher numbers mean milder winters. Your zone tells you which perennial plants can survive winter outdoors at your location without additional protection.
The USDA updated its map in November 2023 — the first update in 11 years — using 30 years of data from 1991–2020. About half of the contiguous US shifted to a warmer half-zone. If you haven’t checked your zone since before 2023, it may have changed. This affects which perennials you can reliably grow and which border plants may now survive your winters.
Zones measure only average minimum winter temperatures. They don’t account for summer heat, humidity, rainfall, soil type, wind exposure, or spring/fall frost timing. A plant rated for Zone 7 will survive your winter in Zone 7, but it may still struggle with drought in Texas or summer humidity in Georgia. Use zones as your first filter, not your only filter.
Each zone is divided into two 5°F subzones. The “a” subzone is the cooler half; “b” is the warmer half. For example, Zone 6a has average winter lows of −10°F to −5°F, while Zone 6b averages −5°F to 0°F. If you’re near a zone boundary, the subzone designation can make a real difference for borderline plants. Always use the subzone when selecting marginally hardy plants.
Use this table to understand every zone’s winter temperature range, typical regions, and growing season length. Enter your ZIP code in the tool above for your exact zone.
| Zone | Winter Low (°F) | Typical Regions | Growing Season | Signature Plants |
|---|---|---|---|---|
| 3 | −40°F to −30°F | Northern MN, ND, MT highlands | 90–120 days | Siberian iris, wild bergamot, spruce |
| 4 | −30°F to −20°F | Northern WI, VT, ME, MI Upper Peninsula | 120–150 days | Coneflower, hosta, apple trees |
| 5 | −20°F to −10°F | Chicago IL, Columbus OH, Denver CO | 150–175 days | Daylily, lavender, black-eyed Susan |
| 6 | −10°F to 0°F | St. Louis MO, Philadelphia PA, Portland OR | 175–205 days | Roses, boxwood, peony, fig (protected) |
| 7 | 0°F to 10°F | Washington DC, Nashville TN, Oklahoma City | 205–240 days | Crape myrtle, gardenia, nandina |
| 8 | 10°F to 20°F | Dallas TX, Atlanta GA, Seattle WA | 240–285 days | Camellia, pittosporum, citrus (protected) |
| 9 | 20°F to 30°F | Houston TX, Sacramento CA, Tampa FL | 285–330 days | Bougainvillea, citrus, palms, lantana |
| 10 | 30°F to 40°F | Los Angeles CA, Miami FL, Honolulu HI | 330–365 days | Tropical hibiscus, avocado, bird of paradise |
| 11–13 | 40°F+ | Hawaii (low elevation), Puerto Rico, S. Florida | Year-round | Mango, plumeria, coconut palm, orchids |
Always select perennials, trees, and shrubs rated for your zone or colder. A plant labeled “Hardy to Zone 5” will survive Zone 5 and colder zones. Borderline plants (one zone warmer than yours) can sometimes be grown in protected microclimates — south-facing walls, courtyards, or mulched beds — but carry real risk in harsh winters.
Annual vegetables don’t need to survive winter, so zones aren’t a hard limit for vegetable gardening. What matters for vegetables is your frost-free season length, last spring frost date, and first fall frost date. Use our Frost Date Calculator to find those dates. Most vegetable crops can be grown in Zones 3–10.
You can often grow plants rated one zone warmer by exploiting microclimates. South-facing walls absorb heat and radiate warmth overnight. Raised beds drain faster, avoiding wet-cold root conditions. Urban areas run 2–5°F warmer than suburbs. A heavy mulch layer in fall protects marginally-hardy root systems through your coldest nights.
A plant that’s “zone-appropriate” can still fail from summer heat, drought, waterlogged soil, or late spring cold snaps that damage new growth. Zones only predict winter survival. Read full plant descriptions for heat tolerance, moisture needs, and sun requirements — especially for borderline perennials and tropical-origin shrubs.
A USDA plant hardiness zone is a geographic area defined by its average annual extreme minimum winter temperature. The contiguous US is divided into Zones 3–10 (with 1–2 in Alaska and 11–13 in Hawaii and Puerto Rico). Each zone covers a 10°F temperature range and is divided into “a” and “b” subzones covering 5°F each. Gardeners use zones to choose plants that can survive winter outdoors in their area.
The fastest way is to enter your ZIP code in the finder tool at the top of this page. It returns your zone, subzone, winter temperature range, last frost estimate, growing season length, and recommended plants based on 2023 USDA map data. You can also use the official interactive map at planthardiness.ars.usda.gov for a precise point lookup based on your exact coordinates.
The 2023 map was built using temperature data from 1991–2020, replacing the 2012 map which used 1976–2005 data. About 50% of the US shifted to a warmer half-zone (e.g., from Zone 6a to Zone 6b). This reflects warming winter temperatures over the past three decades. If your zone changed, you may now be able to reliably grow plants that were previously borderline for your area.
Yes, with effort and strategy. Microclimates, winter mulching, south-facing walls, and container growing allow many gardeners to successfully grow plants one zone warmer than their official rating. However, marginally-hardy plants carry real risk during unusually cold winters, which occur more frequently than zone averages suggest. For high-value plantings — expensive trees, established shrubs — always plant within your zone for reliable long-term success.
Not directly. Annual vegetables complete their life cycle in one growing season, so winter cold tolerance is irrelevant. For vegetables, the key metrics are your frost-free season length, last spring frost date, and first fall frost date. Use those dates to time planting and choose varieties with appropriate days-to-maturity for your season. Our Frost Date Calculator provides those figures by ZIP code.
USDA zones can shift significantly over short distances, especially in areas with varied elevation, proximity to large bodies of water, or urban heat islands. A valley bottom traps cold air and may be a half-zone colder than a nearby hillside. A downtown urban area may run 2–4°F warmer than suburban neighborhoods 10 miles away. The USDA map shows average zone, but your specific garden’s microclimate may differ from your mapped zone.
This free tool is designed for home gardeners across the continental United States. Zone data is cross-referenced from the 2023 USDA Plant Hardiness Zone Map (based on 1991–2020 temperature averages) by ZIP code prefix region. Results include your zone, subzone, average winter temperature range, growing season estimate, last frost window, and curated plant recommendations for your specific zone. Results carry a natural ±½ zone variance based on local microclimate conditions.
For your last spring frost and first fall frost dates by ZIP code, use our Frost Date Calculator. To plan vegetable planting schedules, visit our Planting Date Calculator. To calculate how many seeds to plant for your family size, try our Vegetable Seed Calculator.
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