Compositions and related methods for promoting plant growth using irreversibly denatured collagen-based gelatin are described. In one embodiment, a covered plant propagation source comprises a plant propagation source covered by a covering material, the covering material comprising irreversibly denatured collagen-based gelatin. Another embodiment is directed to promoting plant growth by contacting one or more plant propagation sources with irreversibly denatured collagen-based gelatin prior to or during germination of the one or more plant propagation sources.
