The green plant element consists of a seed-mat (10) of flexible decayable material. Seeds (12) are fixed in position at spaced apart points by the seed-mat. At least part of the mat has a dry adhesive (14) which is tolerated by plants. Water acts with the adhesive to stick the seed-mat to a body to be greened until the plants grow roots into the body to secure the mat. The seed mat consists of a bottom (16) and top (18) layer joined together to form a fleece. The seeds and adhesive are arranged between the layers/
