Organic weed control in greenhouses is not always evident. The main reason is the limitation of mechanical weeding methods, especially in the case of extant pipe rail heating. Different methodologies were compared in the past few years, both in heated greenhouses and in a dome during cultivation or between two crops.
In a heated greenhouse with fruiting crops, the use of poultry proves surprisingly successful. Tests in a Belgium research trial show that the deployment of Japanese quail gives good results. A sufficiently large quantity of these animals, possibly in combination with Australian Wood Ducks or Silkies (sometimes alternatively spelled Silky, a breed of chicken named for its atypically fluffy plumage) might prove remarkably effective.
Be sure to provide the little critters with sufficient drinking water and additional nutrition.