Where the data comes from
This is the main thing that sets the app apart: everything it claims has a source, and the source is named. Where there is no source, the app says nothing — rather than inventing something plausible.
FAO ECOCROP
What a crop needs from a place. Temperature, pH, rainfall, cycle length, light. Licensed CC BY 4.0. These are the thresholds behind the app telling you whether a crop will have time to ripen and whether a perennial will survive the winter.
Russian Ministry of Agriculture register
Treatments and waiting periods. Only entries registered for household plots are shown: those give the dose in domestic units — “40–50 g per 10 l of water”. Industrial dosages are not shown at all.
BVL (Germany)
The same, for a German garden. The two registers are never mixed: each has its own heading in the card, and the foreign one carries a note about the border.
iNaturalist
When a crop flowers and fruits. From annotated observations. The season is always shown together with how many records it rests on; below fifty, no season is named at all.
Russian state variety register
Varieties and growing zones. Structured fields — maturity group and growing conditions — rather than parsing free text.
Wikimedia Commons and Wikipedia
Photographs and descriptions. Only under a free licence — CC0, CC BY, CC BY-SA or public domain. The author and licence are printed under every photograph and cannot be turned off.
Open-Meteo
Weather and archive by coordinates. From a city name you type in yourself. The app never asks for location permission anywhere.
What the app works out itself
The app works out three values itself: the position of the sun and the shade on your plot, the fertilizer a bed needs given your soil and water, and planting density. Each follows published formulas, and each has a “how this is calculated” section with the constants the calculation runs on.
These sections are free and stay free. What the subscription includes.
What the app does not do
Diagnosing a disease from a photograph. A model would produce a claim with no source — precisely what is not done here anywhere.