https://knowledge.growingthecommons.org/ 2026-05-06T04:05:59+00:00 https://knowledge.growingthecommons.org/ https://knowledge.growingthecommons.org/lib/exe/fetch.php/favicon.ico text/html 2026-03-26T18:33:37+00:00 Anonymous (anonymous@undisclosed.example.com) https://knowledge.growingthecommons.org/doku.php/grho/greenhouses?rev=1774550017&do=diff This topic is part of Gardening, smallholding & farming. Greenhouses & polytunnels [Greenhouses & polytunnels] ---------- ""Who loves a garden loves a greenhouse too." - William Cowper" What are greenhouses and polytunnels? Greenhouses and polytunnels are permanent or semi-permanent structures made of transparent material such as glass or plastic that protect plants from the cold and wind. They allow through the whole spectrum of sunlight, but trap the (infra-red) radiation that is reflec…