Stimroot #3 Rooting Hormone (for Hardwood Cuttings) 397 helps to improve the success rate of hard tissue cuttings. Simply touch the end of the cutting into the Stimroot powder, shake off excess and plant the cutting in your rooting medium of choice. 25 g (1 oz.) container. Growing tip – always cut across the stem at a sharp angle as this exposes more of the tissue from which new roots will emerge.