CemStrands
When we developed CemStrands (horizontal in the picture below) we used plant roots as our guide. The picture shows CemForce, designed for use in concrete, being used as a garden screen; plants grow up and even through the CemForce. We use a filled acrylic paint to colour and to block UV. If a plant can find its way through, so can a mortar mix. The fibres in the mesh openings toughen the matrix.
CemStrands and CemForce