About the project

About Safe to Plant

Safe to Plant publishes local frost estimates and planting calendars to help you decide what to grow, when to start and what to check before planting.

What the site provides

Browse 11,509 locations in 188 countries and calendars for 307 crops. Compare cautious, balanced and earlier planting dates, check seasonal conditions, and save a shortlist in My Garden.

Who publishes it

The publisher is Safe to Plant. The project combines public climate data, published horticultural guidance and software calculations. It is not an official weather service, and citing NASA or an extension service does not mean that organisation has endorsed or reviewed this site.

Crop guidance is an editorial summary with references where provided. No horticultural qualifications or expert review are claimed. For a valuable perennial planting or an unfamiliar local crop, seek advice from a nursery or extension service familiar with your conditions.

Where the data comes from

Temperature calculations use NASA POWER daily records for 1995–2024. Rainfall context uses the separate NASA POWER corrected precipitation climatology for 2001–2020. These are gridded estimates, so a nearby hill, coast or sheltered garden can differ substantially.

Place names and coordinates come from GeoNames. Crop requirements and practical notes come from published growing guidance; individual editorial guides link to their references. The method page explains the calculations and their limits.

How to assess the advice

• Frost dates describe historical risk, not this year's forecast.
• Soil-warming dates are estimates from air temperatures. Measure your own soil.
• Frost-free conditions do not establish suitability: rainfall, heat, chill requirements and cultivars still matter.
• A “source checked” date records an editorial reference check, not an expert assessment or a new climate observation.

If a figure conflicts with a reliable local record, use the correction link on the page and include the figure, location and evidence. Contact Safe to Plant.

Access and advertising

The calendars and saved garden are free to use. The site may display advertising. Advertising and analytics services are described in the privacy policy.

Editorial and correction process

We separate three kinds of information: calculated climate estimates, summaries of published cultivation guidance, and observations reported by growers. References support the linked cultivation advice; they do not certify every crop-and-town combination. We do not present a model output as a local field trial.

A useful correction includes the page URL, crop and cultivar, approximate location, dates, growing conditions and a source or observation. We check the evidence against the calculation before changing advice. One successful season is useful context, but is not proof that the same result is reliable everywhere nearby.

The growing record worksheet helps visitors keep comparable observations. There are currently no independently reviewed field trials published by this project. External reviews, photographs and reported results will be identified accurately if added.

Using the information

Use the dates to plan, then check the forecast and conditions in your bed or container. Terms of use and attribution explain reuse of the site's derived data.

Publisher information updated 18 September 2026.