1. Porous and water-permeable element for plant culture (6) containing particles (2) containing an excess of hydrophilic Darticles, preferably relatively incompressible in the dry state, characterized in that the particles (2) are attached to each other essentially by a limited number of points of contact (9), together forming substantially capillary channels (10), these particles (2) having substantially the following particle size distribution, expressed using standard US sieves : Sieve number Retained on the sieve by weight + 18 0-5% - 18/+ 30 5-10% - 30/+ 50 10-35% - 50/+ 100 20-35% - 100/+ 150 10-25% - 150/+ 200 5-15% - 200 10-20%
