Climate Zones
Not sure what will actually grow in your garden? Climate zones turn your winter cold, summer heat, and local weather patterns into simple guides that help you choose plants built for your environment.
This page explains the three major systems—USDA Plant Hardiness Zones, AHS Heat Zones, and Sunset Climate Zones—and connects you with plant lists, garden ideas, and combinations that match your growing conditions.
Quick tools for your climate-smart garden
How to use this climate zone directory
Use the maps and filters below to identify your USDA hardiness zone, AHS heat zone, and—if you garden in the West—your Sunset climate zone. Once you know your zone, you can:
- Select plants that thrive in your winter lows, summer highs, and seasonal patterns.
- Combine cold hardiness with heat tolerance for stress-free planting.
- Explore regional garden ideas tailored to your climate.
Matching plants to your planting zone is the easiest way to build a resilient, low-maintenance, and climate-adapted garden.
What are USDA Plant Hardiness Zones?
USDA Plant Hardiness Zones classify regions by their average annual minimum winter temperature. This system shows which plants can reliably survive the cold in your area.
Use your USDA hardiness zone to:
- Confirm whether trees, shrubs, and perennials are winter-hardy where you live.
- Compare your zone with plant tags and online plant profiles.
- Decide which plants return each year and which should be treated as annuals.
Learn more in our guides:
Hardiness Zones 101, the complete Hardiness Zone Plant Directory, and regional maps for the
United States, Europe, Australia, and Canada.
What are AHS Heat Zones?
AHS Heat Zones show how many days per year exceed 86°F (30°C)—the temperature at which many plants begin to experience heat stress. Heat tolerance is just as important as cold hardiness.
Knowing your heat zone helps you:
- Choose plants that remain productive and healthy through intense summer heat.
- Place heat-loving species in full sun and shelter cool-climate plants in partial shade.
- Plan irrigation and mulching strategies that reduce stress and conserve water.
For the best results, evaluate both your USDA hardiness zone and AHS heat zone before planting.
What are Sunset Climate Zones?
Sunset Climate Zones provide one of the most precise ways to match plants to local conditions in the western United States. These zones consider not just temperature, but also rainfall, humidity, elevation, wind, and ocean influence.
Sunset zones apply across the western states: Alaska, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming.
Sunset zones factor in:
- Winter lows and summer highs
- Length of the growing season
- Rainfall patterns, humidity, and prevailing winds
- Elevation and proximity to the ocean
If you garden in the West, your Sunset climate zone is often the best guide for selecting and placing plants.
Deep-dive guides on hardiness, heat & climate zones
Ready to go deeper? These guides explain how climate zones work and how to apply them using Gardenia’s tools:
Once you’ve identified your climate zone, use the Plant Finder, Garden Finder, and Plant Combinations to choose plants and designs perfectly matched to your climate.
