Where the numbers come from
Data sources
Every dataset and guide behind HolaGrower's advice, and what each one is used for.
How HolaGrower uses data
Advice in the app is built from published datasets and extension-service guides, applied to where you actually
garden. When the app shows a figure that comes from one of these sources, the source is named right beneath it.
This page lists every source the app currently uses and what each one is used for.
Open-Meteo
Weather forecast and history
Current conditions and the 7-day forecast on the Weather screen, and the historical weather record behind your climate profile. The daily gardening notes are simple rules based on the forecast temperature and sky, and the app says so.
ERA5 reanalysis
Copernicus Climate Change Service / ECMWF
Ten years of measured weather at your garden's coordinates (retrieved through Open-Meteo). From it the app works out your frost dates, growing-season length, rainfall pattern and hardiness zone, and which months suit each crop's temperature range where you are.
Köppen–Geiger climate classification
Published classification rules
Your climate type (for example “humid subtropical”), calculated from the ERA5 record above using the published rules.
UNH Cooperative Extension
University of New Hampshire
The planting calendar for 34 crops, timed from the last and first frost. The app shifts it to your own frost dates.
USDA planting and harvesting dates
US Department of Agriculture
For US gardens, the usual planting and harvesting windows for your state (Agricultural Handbook 628, “Usual Planting and Harvesting Dates for U.S. Field and Vegetable Crops”).
Texas A&M AgriLife Extension
Publication E-545
Recommended container sizes for 14 crops, used when you plan container beds.
WVU Extension
West Virginia University
Plants per square for square-foot gardening (11 crops), used to suggest how many plants fit in a bed.
Google Gemini
AI model by Google
Plant identification, diagnosis and follow-up answers. These are AI estimates: every result shows a confidence score, and for serious problems we recommend checking with your local extension office.
What isn't tied to a single source yet
Some plant-profile details in the catalog (temperature ranges, days to harvest, watering, companion plants and
common pests) are general guidance compiled by HolaGrower, not figures from one published source. They're shown as
guidance, and we're replacing them with extension-service data crop by crop. This page will be updated as that
happens.
Spotted something wrong?
If a figure in the app doesn't match your experience or a source above, tell us at support@holagrower.com
and include the plant and your location. We check every report.