The aim of this study is to find a way to improve the mechanical characteristics of green plastering based on clay and wheat straw. Wheat straw is waste from agriculture, which most often are burnt in the fields, thus contributing to higher emissions of carbon dioxide. The study's objective is to achieve green mortars based on clay. To improve the mechanical characteristics, the influence of wheat straw as a reinforcing material was studied. It was studied how the geometric characteristics of wheat straw affect the properties of studied material.