Find Your Planting Zone and Frost Dates by ZIP Code
Which pond plants will feel at home in your pond? Enter your ZIP code to find your USDA planting zone and typical last spring and first fall freeze dates, then use both to plan what to plant and when.
How to read your results
Your zone helps you choose plants. The USDA 2023 Plant Hardiness Zone Map describes your area's average annual coldest winter temperature. Zones run from 1 (coldest) to 13 (warmest), each covering 10°F. The letters divide each zone into 5°F halves, so 7b is warmer than 7a.
Use your zone to assess winter hardiness. It does not tell you summer temperatures, growing-season length, or when freezing weather arrives.
Your freeze dates help you plan timing. These estimates use NOAA's 1991 to 2020 climate normals and the 50% probability dates for temperatures reaching 32°F or below. At a weather station, that means the last spring freeze falls before that date in roughly half of years and after it in the other half. The first fall freeze follows the same midpoint principle.
Often called "frost dates," these are specifically 32°F freeze dates. Frost can occur even when the reported air temperature stays above freezing.
Same zone, different dates. Two places can share a zone but have different freeze seasons. Use your zone for plant selection and your dates for seasonal planning.
How local are the results?
A ZIP code can span multiple elevations, microclimates, and mapped zones. For a closer look, especially near zone boundaries or in mountainous areas, check your location on the USDA interactive map.
Our freeze estimates combine NOAA data from up to three nearby stations, excluding those with large elevation differences. For most ZIP codes, the nearest station used appears with your results.
Terrain, nearby water, pavement, and buildings can affect your pond's conditions. These dates are planning guides, not guarantees. Watch the local forecast, allow extra time beyond the spring midpoint for tender plants, and check water temperatures before planting.
Putting your zone and dates to work
Check each plant's listed hardiness and growing requirements. Botanical names help distinguish plants with similar common names.
| Plant type | What to watch |
|---|---|
| Hardy water lilies | Match the variety to your zone and protect its rhizome from freezing solid. Spring planting also depends on water temperature and whether the plant is dormant or actively growing. |
| Tropical water lilies | Often grown seasonally in colder climates. Wait until freeze risk has passed and water stays around 70°F or warmer. Plan fall protection before cold conditions damage them. |
| Lotus | Many are winter-hardy when their tubers remain unfrozen. They also need warmth and sun to grow well. Freeze dates help estimate the frost-free season, but do not measure summer heat. |
| Floating plants | Water hyacinth and water lettuce are tender and commonly treated as annuals in freezing climates. Introduce them when frost risk has passed and conditions are warm; remove them before damaging cold. Check shipping restrictions and state rules before ordering. |
| Oxygenating and submerged plants | Hardiness varies. Plants such as hornwort can overwinter in suitable ponds, but check the species' range and winter requirements. Surface freeze dates alone do not describe underwater conditions. |
| Marginal and bog plants | This group includes hardy iris, pickerel rush, and cardinal flower, plus plants such as papyrus, taro, and canna whose winter survival depends on species, cultivar, and climate. Match hardiness to your zone and use seasonal temperatures to time planting and protection. |
When to order pond plants
Our Earliest Recommended Plant Shipping Times lists suggested timing for hardy and tropical plants by whole zone number. For example, use the Zone 8 row for Zone 8b.
Planning ahead for fall
Use your first fall freeze estimate as a planning reminder, but act sooner if the forecast or your plant's temperature requirements call for it. For plant-by-plant instructions, visit Winterizing Pond Plants.
Frequently asked questions
What planting zone am I in?
Enter your ZIP code in the lookup above. You will see your USDA planting zone, including the "a" or "b" half. If you live near a zone boundary or in hilly country, confirm it on the USDA interactive map.
When is the last frost in my area?
The lookup shows the typical last spring freeze for your area, based on NOAA weather stations near you. It is a midpoint, so a freeze can still arrive after it in some years. Watch your local forecast before putting out tender plants.
When is the first frost in my area?
The lookup shows the typical first fall freeze for your area, based on NOAA weather stations near you. Use it as a heads-up for when cold-sensitive plants may need protection.
Is my planting zone the same as my frost date?
No. Your zone describes how cold winter gets, and your freeze dates describe when the cold season starts and ends. Use the zone to choose plants and the dates to time planting and protection.
Keep exploring
- Pond Plants
- Pond Plant Buyer's Guide
- Winterizing Pond Plants
- Earliest Recommended Plant Shipping Times
Sources
Zone data: USDA Plant Hardiness Zone Map, 2023 (USDA Agricultural Research Service and Oregon State University PRISM Group). Freeze data: NOAA NCEI U.S. Climate Normals 1991 to 2020. ZIP code locations: U.S. Census Bureau ZIP Code Tabulation Area Gazetteer.