"Policy changes in Belgium in relation to cannabis use, possession and cultivation may also have had some impact on the shift in production from the Netherlands to Belgium. In 2001, the Belgian government agreed to stop prosecution for use of cannabis and cultivation of cannabis for personal use, on the grounds that it did not constitute a nuisance and was not problematic (Decorte, 2007). However, it was not until 2003 that guidelines outlining what was permitted were implemented. Under the new guidelines, cultivation of cannabis for personal use (one female plant) and possession of up to 3 grams are no longer grounds for prosecution (Decorte, 2007). The action to be taken in cases of larger amounts is left to the discretion of the prosecutor, leaving the boundaries of cultivation limits unclear."

Source

"EMCDDA Insights: Cannabis production and markets in Europe," European Monitoring Centre for Drugs and Drug Addiction (Lisbon, Portugal: 2012), p. 74.
http://www.emcdda.europa.eu/a…