Could you please explain what it means ?
Excerpt from the wikipedia article [1]:
> The first part of the phrase is often remembered as "let a hundred flowers bloom". It is used to refer to an orchestrated campaign to flush out dissidents by encouraging them to show themselves as critical of the regime, and then subsequently imprison them. This view is supported by authors Clive James and Jung Chang, who posit that the campaign was, from the start, a ruse intended to expose rightists and counter-revolutionaries, and that Mao Zedong persecuted those whose views were different from the party's.
Many who expressed critical opinions ended up under investigation and in prison labour camps.
The short version is that Mao encouraged people to openly express non-communist political philosophies and then killed or imprisoned those who had done so.