Semiterra
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Legal notice

Last updated: 30 September 2026

Publisher

The Semiterra website, available at semiterra.com, is published by Veltone SAS, a simplified joint-stock company with a sole shareholder and a share capital of €10.00, whose registered office is at 1126 Rue des Allobroges, 74140 Saint-Cergues, France.

Registered with the Thonon-les-Bains Trade and Companies Register under number 103 159 885 — SIRET 103 159 885 00013 — VAT number FR03103159885.

Publication director: Laurent CALON.

Contact: contact@semiterra.com.

Host

The website is hosted by Google Cloud EMEA Limited (Firebase Hosting service), Google Cloud France SARL, 8 Rue de Londres, 75009 Paris, France — phone: +33 1 42 68 53 00. It is a static website delivered through Google's content delivery network.

Intellectual property

The Semiterra trademark and all content of the website (text, calendars, interfaces, graphics, structure and data compilation) are protected by intellectual property law and remain the property of Veltone SAS or its partners. Any reproduction, representation, adaptation or extraction, in whole or in part, without prior written authorisation, is prohibited.

The illustrations of the blog articles are generated by artificial intelligence. The site icon comes from the Tabler Icons library (MIT licence).

Data sources

Frost dates and heat indicators are computed by Semiterra from the following data, reused in accordance with their licence. Semiterra has transformed them: the daily records for 1991-2020 are summarised as median frost dates and monthly mean temperatures, then interpolated for each town and corrected for its altitude. Citing these sources does not imply any endorsement of Semiterra by their producers.

Weather stations

  • France — Météo-France, daily basic climatological data (Licence Ouverte Etalab 2.0);
  • Germany — “Datenbasis: Deutscher Wetterdienst, Einzelwerte gemittelt” (CC BY 4.0);
  • Austria — “Datenquelle: GeoSphere Austria https://data.hub.geosphere.at” (CC BY 4.0);
  • Switzerland — “Source: MeteoSwiss” (CC BY 4.0);
  • Belgium — Royal Meteorological Institute of Belgium (RMI), synoptic observations (CC BY 4.0);
  • Netherlands — KNMI, daily climatological data (CC BY 4.0);
  • Luxembourg — MeteoLux, daily parameters for Luxembourg-Findel (CC0);
  • Ireland — “Copyright Met Éireann. Source www.met.ie. This data is published under a Creative Commons Attribution 4.0 International (CC BY 4.0). https://creativecommons.org/licenses/by/4.0/. Met Éireann does not accept any liability whatsoever for any error or omission in the data, their availability, or for any loss or damage arising from their use. This material has been modified from the original: daily station temperatures summarised as 1991-2020 frost dates and monthly means.”

Towns, postcodes and altitude

  • France — geo.api.gouv.fr (communes) and IGN, Géoplateforme altimetry service (Licence Ouverte Etalab 2.0);
  • Germany — “Quelle: Gemeindeverzeichnis-Informationssystem GV-ISys, Statistische Ämter des Bundes und der Länder”;
  • Austria — “Datenquelle: Statistik Austria — data.statistik.gv.at” (CC BY 4.0);
  • Switzerland — © swisstopo (official directory of localities) and FSO (communes and population);
  • Belgium — Wikidata (CC0);
  • Luxembourg — Administration du cadastre et de la topographie (ACT) and Registre national des personnes physiques (CC0);
  • Ireland — Tailte Éireann (Centres of Population) and Central Statistics Office (population), CC BY 4.0;
  • Postcodes outside France — GeoNames, www.geonames.org (CC BY 4.0);
  • Altitudes outside France — “produced using Copernicus WorldDEM-90 © DLR e.V. 2010-2014 and © Airbus Defence and Space GmbH 2014-2018 provided under COPERNICUS by the European Union and ESA; all rights reserved”. The organisations in charge of the Copernicus programme, by law or by delegation, do not incur any liability for any use of Copernicus WorldDEM-90.

Growing calendars and companion planting are based on public sources cited on each plant page. Those sources remain the property of their authors.

Personal data

The processing of personal data is described in our privacy policy. The rules for using the website are set out in our terms of use.

Liability

The sowing, planting and harvest dates given by Semiterra are averages, computed from historical climate data and reference calendars. They are provided for information only: the weather of a given year, the exposure and the soil of your garden may call for adjustments. They do not constitute professional advice, and Veltone SAS accepts no liability for the results of your crops.

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