Artificial seeds characterized in that they comprise: a meristematic tissue, a support contacting, and preferably fully enclosing said meristematic tissue, the support being: a) a non compact solid including, when exposed to the air and in its dried state, a volume proportion of air of at least 10 %, preferably at least 50 %, b) gas and/or steam permeable, preferably air and water vapour permeable, c) dry or dryable, a hydrosoluble polymeric envelope enclosing the entire support and meristematic tissue, a water resistant film covering the inner surface of the polymeric envelope.