Abstract: Supporting structure for seed beds, in particular for cultivating mushrooms, which construction consists of a number of evenly spaced parallel longitudinal girders, whose upper sides form a bearing surface for a synthetic cloth which can be pulled along the upper sides and in the longitudinal direction of the girders by means of mechanical means, during which movement of the cloth garden mould, compost, manure and the like is deposited on the cloth or removed therefrom, whereby the bearing surface for the cloth formed by the upper sides of the girders is provided with a profile in order to reduce the friction between the cloth and the girders.