A coherent growth substrate product formed of man-made vitreous fibres (MMVF) bonded with a cured binder composition and a wetting agent is described, wherein the binder composition prior to curing comprises the following components: - a component (i) in form of one or more carbohydrates; - a component (ii) in form of one or more compounds selected from sulfamic acid, derivatives of sulfamic acid or any salt thereof. Use of said coherent growth substrate product for growing plants and propagating seeds is also disclosed. In addition, a process for making said coherent growth substrate product is disclosed.
