Plant Hardiness Zone Calculator

Find minimum temperature, recommended plants, and planting season by USDA zone.

Min Temp Range

0 to 10 °F

Planting Season

Mar – Nov

Zone Details

USDA Zone7
Min Temperature0 to 10 °F
Common PlantsFigs, crepe myrtles, camellias
Planting SeasonMar – Nov
Frost Protection TipsWrap young trees in cold snaps

Use the Plant Hardiness Zone Calculator above to calculate your results. Enter your values and see instant results — all calculations run in your browser.

Disclaimer: This calculator is for informational purposes only and does not constitute tax, financial, or legal advice. Results are estimates based on the information you provide and current rates. Always consult a qualified tax professional or financial advisor for advice specific to your situation.

How It Works

Our Plant Hardiness Zone Calculator helps you identify your USDA Plant Hardiness Zone based on your location, providing crucial information for successful gardening. Knowing your zone is essential because it determines the average annual minimum winter temperature, which directly impacts which plants can survive and thrive in your area. For 2026, the USDA has confirmed no major shifts in zone boundaries, ensuring the data remains consistent with recent years.

This calculator utilizes the official USDA Plant Hardiness Zone Map data, which is based on the average annual extreme minimum winter temperature, divided into 10-degree Fahrenheit zones. Each zone is further divided into 'a' and 'b' subzones, representing 5-degree Fahrenheit increments. Upon entering your zip code or location, the tool cross-references this with the USDA's geospatial database to pinpoint your precise zone and its associated temperature range.

Remember that microclimates can exist within a single zone due to factors like elevation, proximity to water bodies, or urban heat islands, so observe your local conditions. While the zone provides a good guideline for plant survival, it doesn't account for summer heat, soil type, or rainfall, which are also vital for plant health. A common mistake is planting a 'zone 5' plant in a 'zone 4' area, expecting it to survive without significant winter protection.

Example: Planning a New Garden in Denver, Colorado

  1. 1 You're planning a new garden in Denver, Colorado, zip code 80202, and want to know which plants will survive the winter without special care. You enter '80202' into the calculator.
  2. 2 The calculator processes the zip code against the USDA Plant Hardiness Zone database. It identifies Denver, CO (80202) as being primarily within USDA Zone 5b.
  3. 3 Result: Your USDA Plant Hardiness Zone is 5b. The average annual extreme minimum winter temperature for Zone 5b is -15°F to -10°F.
  4. 4 Context: For 2026, this means you should select plants rated for USDA Zone 5 or lower to ensure they can withstand Denver's typical winter temperatures. Recommended planting seasons for many perennials and shrubs in Zone 5b are typically spring (after the last frost, usually mid-May) or early fall, allowing roots to establish before winter.

Source: NWS · Last updated: April 2026

Frequently Asked Questions

What is a USDA hardiness zone?
USDA hardiness zones divide the US into 13 zones based on average annual minimum winter temperature. Each zone covers a 10-degree range. Zone 1 has minimums below -50F and Zone 13 above 65F. Most of the continental US falls in zones 3-10.
What can I plant in my hardiness zone?
Your zone number tells you the minimum cold tolerance plants need to survive winter. Zone 6 (-10F to 0F) can grow most deciduous trees, many perennials, and cool-season vegetables. Heat tolerance, rainfall, and soil type also matter for plant selection.
Has my hardiness zone changed due to climate change?
Yes. The USDA updated the hardiness zone map in 2023, and roughly half of the country shifted to a warmer half-zone compared to the 2012 map. This means many gardeners can now successfully grow plants that were previously too tender for their area.

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